improve code spec, add one for code-tunnel, upstream the changes to fig

[meganrogge]

• We should add things like:
  • --locate-shell-integration-path Add --locate-shell-integration-path to code fig spec #242467
• add a spec for code-tunnel with all of its properties
• Generators for uninstall-extension Provide custom args for code options #240237

[Tyriar]

Generated fig spec from the native CLI. It's very repetitive so we should merge the useful parts in:

fig.ts.txt

[meganrogge]

Notes from @Tyriar via correspondence with Connnor:

• We won't try differentiate code.exe and code and assume they act the same.
• We'll add a code-tunnel completion spec which will point at the code one since the native CLI should support the same things. This is what we do with code-insiders which is just code with a special name
• We'll add tunnel and serve-web subcommands to the code spec (we may need your help here)
• Then in the future, any changes we do to the CLI make sure you consider the completions as well, either making the change yourself or pinging us to update it.