update Lightning LSPs to 2.1.0 / add new activation logic

[nrkruk]

What does this PR do?

• Update the lightning lsps to 2.1.0
• Fix settings.json file being overwritten
• Async startup for aura language server
• Add vscode settings for configuring LSP activation
• Cleanup activation logic for internal and external developers

What issues does this PR fix or reference?

#1210

[codecov]

Codecov Report

Merging #1253 into develop will increase coverage by 0.16%.
The diff coverage is 0%.

@@             Coverage Diff             @@
##           develop    #1253      +/-   ##
===========================================
+ Coverage    72.61%   72.78%   +0.16%     
===========================================
  Files          203      202       -1     
  Lines         7425     7403      -22     
  Branches       776      773       -3     
===========================================
- Hits          5392     5388       -4     
+ Misses        1868     1849      -19     
- Partials       165      166       +1

Impacted Files	Coverage Δ
...code-lightning/src/commands/quickpick/quickpick.ts	0% <0%> (ø)	⬆️
...ode-lightning/src/views/component-tree-provider.ts	0% <0%> (ø)	⬆️
...forcedx-vscode-core/src/channels/channelService.ts	83.33% <0%> (-2.39%)	⬇️
...salesforcedx-vscode-lwc/src/dxsupport/waitForDX.ts

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[nrkruk]

This is the same PR as (#1231), but with cleanup / comments addressed

[lcampos]

@AnanyaJha this fixes the compile issue we're seeing this morning with using version 6.2.0.