Bump ejs, @microsoft/generator-sharepoint and webpack-bundle-analyzer

Bumps [ejs](https://github.com/mde/ejs) to 3.1.10 and updates ancestor dependencies [ejs](https://github.com/mde/ejs), [@microsoft/generator-sharepoint](http://aka.ms/spfx) and [webpack-bundle-analyzer](https://github.com/webpack-contrib/webpack-bundle-analyzer). These dependencies need to be updated together.


Updates `ejs` from 2.6.1 to 3.1.10
- [Release notes](https://github.com/mde/ejs/releases)
- [Commits](mde/ejs@v2.6.1...v3.1.10)

Updates `@microsoft/generator-sharepoint` from 1.4.1 to 1.19.0

Updates `webpack-bundle-analyzer` from 2.13.1 to 4.10.2
- [Changelog](https://github.com/webpack-contrib/webpack-bundle-analyzer/blob/master/CHANGELOG.md)
- [Commits](webpack-contrib/webpack-bundle-analyzer@v2.13.1...v4.10.2)

---
updated-dependencies:
- dependency-name: ejs
  dependency-type: indirect
- dependency-name: "@microsoft/generator-sharepoint"
  dependency-type: direct:production
- dependency-name: webpack-bundle-analyzer
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>