Move constants from webview to platform

[rebornix]

Re #10152

We have global constants stored in src/webviews/webview-side/common/constants, which can now be moved to src/platform/common/constants.

• 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).

[codecov-commenter]

Codecov Report

Merging #10453 (b36f83b) into main (d51447d) will decrease coverage by 0%.
The diff coverage is 100%.

@@          Coverage Diff           @@
##            main   #10453   +/-   ##
======================================
- Coverage     70%      70%   -1%     
======================================
  Files        480      480           
  Lines      28950    28949    -1     
  Branches    4859     4860    +1     
======================================
- Hits       20520    20508   -12     
- Misses      6531     6537    +6     
- Partials    1899     1904    +5     

Impacted Files	Coverage Δ
src/kernels/jupyter/types.node.ts	100% <ø> (ø)
src/extension.node.ts	76% <100%> (ø)
...-window/debugger/interactiveWindowDebugger.node.ts	68% <100%> (ø)
...s-message-coordination/commonMessageCoordinator.ts	60% <100%> (ø)
...message-coordination/ipyWidgetMessageDispatcher.ts	77% <100%> (ø)
...nels/jupyter/import-export/jupyterExporter.node.ts	33% <100%> (+<1%)	⬆️
...nels/jupyter/import-export/jupyterImporter.node.ts	60% <100%> (ø)
...kernels/jupyter/interpreter/jupyterCommand.node.ts	48% <100%> (ø)
...preter/jupyterInterpreterDependencyService.node.ts	75% <100%> (ø)
...pyterInterpreterSubCommandExecutionService.node.ts	90% <100%> (ø)
... and 25 more