delay showing install python commands until after controllers are loaded

[IanMatthewHuff]

Fixes #10960

• Pull request represents a single change (i.e. not fixing disparate/unrelated things in a single PR).
• Title summarizes what is changing.
• Has a news entry file (remember to thank yourself!).
• Appropriate comments and documentation strings in the code.
• Has sufficient logging.
• Has telemetry for feature-requests.
• Unit tests & system/integration tests are added/updated.
• Test plan is updated as appropriate.
• package-lock.json has been regenerated by running npm install (if dependencies have changed).

[IanMatthewHuff]

Added a gate for the view here. If we fix context in the kernel picker commands this can be moved to the when, but that support is not there yet.

[codecov-commenter]

Codecov Report

Merging #11430 (4a8df3f) into main (428405b) will decrease coverage by 0%.
The diff coverage is 100%.

❗ Current head 4a8df3f differs from pull request most recent head f5692da. Consider uploading reports for the commit f5692da to get more accurate results

@@           Coverage Diff           @@
##            main   #11430    +/-   ##
=======================================
- Coverage     63%      63%    -1%     
=======================================
  Files        476      477     +1     
  Lines      33976    34154   +178     
  Branches    5508     5544    +36     
=======================================
+ Hits       21560    21603    +43     
- Misses     10357    10499   +142     
+ Partials    2059     2052     -7     

Impacted Files	Coverage Δ
...ollers/commands/installPythonControllerCommands.ts	57% <100%> (ø)
src/notebooks/controllers/controllerLoader.ts	92% <100%> (+4%)	⬆️
src/kernels/jupyter/serverSelector.ts	43% <0%> (-19%)	⬇️
src/platform/common/platform/fileSystem.ts	35% <0%> (-9%)	⬇️
.../standalone/survey/dataScienceSurveyBanner.node.ts	66% <0%> (-6%)	⬇️
src/kernels/kernelStartupCodeProvider.node.ts	76% <0%> (-6%)	⬇️
...interactive-window/debugger/startupCodeProvider.ts	87% <0%> (-4%)	⬇️
src/kernels/jupyter/launcher/serverUriStorage.ts	64% <0%> (-4%)	⬇️
src/platform/common/platform/fileSystem.node.ts	67% <0%> (-3%)	⬇️
src/platform/common/application/extensions.node.ts	84% <0%> (-3%)	⬇️
... and 18 more