Update d3 from version 5.9.2 to 6.7.0

Summary:
Update the d3 library to its last 6.x version available on https://github.com/d3/d3/releases

This also requires updating the tooltip event handling of dots in `Chart.js` to avoid an `Uncaught TypeError: d3.event is undefined` per https://observablehq.com/@d3/d3v6-migration-guide#event-management linked from https://github.com/d3/d3/releases/tag/v6.0.0

Closes T15820

Test Plan:
* Enable the Facts application, go to the Reports of a Project with task changes over time, look at charts, hover over data points, read the tooltip - e.g. on http://phorge.localhost/project/reports/1/ or http://phorge.localhost/maniphest/report/burn/
* Check HTML source of above URIs for the `<script type="text/javascript">` loading `d3.min.js` and open the JS file to verify the d3 version number bump.
* Check Console of web browser's developer tools for no errors.

Reviewers: O1 Blessed Committers, speck

Reviewed By: O1 Blessed Committers, speck

Subscribers: speck, tobiaswiese, valerio.bozzolan, Matthew, Cigaryno

Maniphest Tasks: T15820

Differential Revision: https://we.phorge.it/D25631

resources/celerity/map.php

@@ -187,7 +187,7 @@ return array(
     'rsrc/css/sprite-login.css' => '07052ee0',
     'rsrc/css/sprite-tokens.css' => 'f1896dc5',
     'rsrc/css/syntax/syntax-default.css' => 'c0307dc6',
-    'rsrc/externals/d3/d3.min.js' => '9d068042',
+    'rsrc/externals/d3/d3.min.js' => 'e97b4b78',
     'rsrc/externals/font/fontawesome/fontawesome-webfont.eot' => '23f8c698',
     'rsrc/externals/font/fontawesome/fontawesome-webfont.ttf' => '70983df0',
     'rsrc/externals/font/fontawesome/fontawesome-webfont.woff' => 'cd02f93b',
@@ -558,7 +558,7 @@ return array(
     'conpherence-participant-pane-css' => '69e0058a',
     'conpherence-thread-manager' => 'aec8e38c',
     'conpherence-transaction-css' => '3a3f5e7e',
-    'd3' => '9d068042',
+    'd3' => 'e97b4b78',
     'diff-tree-view-css' => 'e2d3e222',
     'differential-changeset-view-css' => '1b0476bc',
     'differential-core-view-css' => '7300a73e',

webroot/rsrc/externals/d3/LICENSE

@@ -1,4 +1,4 @@
-Copyright 2010-2017 Mike Bostock
+Copyright 2010-2020 Mike Bostock
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without modification,

webroot/rsrc/externals/d3/README.md

@@ -6,10 +6,10 @@
 
 ## Resources
 
+* [Introduction](https://observablehq.com/@d3/learn-d3)
 * [API Reference](https://github.com/d3/d3/blob/master/API.md)
-* [Release Notes](https://github.com/d3/d3/releases)
-* [Gallery](https://github.com/d3/d3/wiki/Gallery)
-* [Examples](https://bl.ocks.org/mbostock)
+* [Releases](https://github.com/d3/d3/releases)
+* [Examples](https://observablehq.com/@d3/gallery)
 * [Wiki](https://github.com/d3/d3/wiki)
 
 ## Installing
@@ -17,19 +17,19 @@
 If you use npm, `npm install d3`. Otherwise, download the [latest release](https://github.com/d3/d3/releases/latest). The released bundle supports anonymous AMD, CommonJS, and vanilla environments. You can load directly from [d3js.org](https://d3js.org), [CDNJS](https://cdnjs.com/libraries/d3), or [unpkg](https://unpkg.com/d3/). For example:
 
 ```html
-<script src="https://d3js.org/d3.v5.js"></script>
+<script src="https://d3js.org/d3.v6.js"></script>
 ```
 
 For the minified version:
 
 ```html
-<script src="https://d3js.org/d3.v5.min.js"></script>
+<script src="https://d3js.org/d3.v6.min.js"></script>
 ```
 
 You can also use the standalone D3 microlibraries. For example, [d3-selection](https://github.com/d3/d3-selection):
 
 ```html
-<script src="https://d3js.org/d3-selection.v1.js"></script>
+<script src="https://d3js.org/d3-selection.v2.js"></script>
 ```
 
 D3 is written using [ES2015 modules](http://www.2ality.com/2014/09/es6-modules-final.html). Create a [custom bundle using Rollup](https://bl.ocks.org/mbostock/bb09af4c39c79cffcde4), Webpack, or your preferred bundler. To import D3 into an ES2015 application, either import specific symbols from specific D3 modules:
@@ -47,11 +47,11 @@ import * as d3 from "d3";
 In Node:
 
 ```js
-var d3 = require("d3");
+const d3 = require("d3");
 ```
 
 You can also require individual modules and combine them into a `d3` object using [Object.assign](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/assign):
 
 ```js
-var d3 = Object.assign({}, require("d3-format"), require("d3-geo"), require("d3-geo-projection"));
+const d3 = Object.assign({}, require("d3-format"), require("d3-geo"), require("d3-geo-projection"));
 ```

webroot/rsrc/js/application/fact/Chart.js

@@ -188,7 +188,7 @@ JX.install('Chart', {
           .attr('r', 3)
           .attr('cx', function(d) { return x(to_date(d.x)); })
           .attr('cy', function(d) { return y(d.y1); })
-          .on('mouseover', function(d) {
+          .on('mouseover', function(event, d) {
             var dd = to_date(d.x);
 
             var d_y = dd.getFullYear();
@@ -215,8 +215,8 @@ JX.install('Chart', {
             div
               .html(view)
               .style('opacity', 0.9)
-              .style('left', (d3.event.pageX - 60) + 'px')
-              .style('top', (d3.event.pageY - 38) + 'px');
+              .style('left', (event.pageX - 60) + 'px')
+              .style('top', (event.pageY - 38) + 'px');
             })
           .on('mouseout', function() {
             div.style('opacity', 0);