Removes strict-boolean-expressions because its too noisy

Avoids unneeded `void`s to know if return value is intentionally discarded
Uses `type` imports when possible (avoids unneeded bundling)

This enables basic multi-select support, but commands have not been audited for proper support and may fail completely or corrupt data (try it at your own risk)

Commands run with multi-select will sequentially execute the command for each selected item (assuming each item is of the same type at the active item, e.g. the item the context menu was shown for), unless they are specifically multi-select aware.

Currently only dropping stashes is now multi-select aware.

- Adds override support to configuration
 - Splits configuration.get into get & getAll
 - Allows passing array to configuration.changed
Avoids getting the entire configuration on startup

Switches to use ansi-regex
Updates to Typescript 4.5-rc
Simplifies the SubPath type
See https://github.com/microsoft/TypeScript/issues/46643#issuecomment-957987115

Adds button to rebase editor to toggle it on/off
Adds commands to toggle rebase editor on/off
Adds settings UI to toggle rebase editor on/off

Giving up on better else/catch/finally formatting -- can't fight anymore
Switching to tabs for better accessibility
https://twitter.com/sh4na/status/1146837957200027648

Moves all lodash into system

Adds bundle analyzer
Adds circular deps analyzer
Switches to es2018 output
Removes many circular dependencies

Updates README (wip)
Updates welcome & settings pages (wip)

Config when's can be resolved before extension activation

Fixes auto-refresh context on repositories view loading

Changes changelog image links to permalinks
Moves all images for docs into a docs folder
Removes unused images

Closes #354 - Adds line history explorer (wip)
Closes #456 - Adds repository status to the repository nodes

Fixes issue with new typescript
Pins node version to match vscode's version (7.9)

Adds menu & toolbar settings to the settings editor
Adds mode setting for settings editor
Adds sticky header to settings editor

Also fixes #286, #227, #219, #186, #151, #104, #75

Adds advanced.fileHistoryFollowsRenames setting
Adds commands to set rename following to the GitLens explorer