[vscode] Support TerminalProfileProvider

[planger]

A TerminalProfileProvider can be registered via window.registerTerminalProfileProvider(id, provider) and eventually provides a TerminalProfile defining how a terminal will be launched. All those types and their support in Theia are currently missing.

The types of the options with which a terminal can be provided already exist:

• TerminalOptions
• ExtensionTerminalOptions

Related VSCode API issues:

• [vscode] Support optional properties iconPath and color in TerminalOptions and ExtensionTerminalOptions #11504
• [vscode] Support Terminal#creationOptions #11138
• [vscode] Support specifying the location in terminal options #11506

[tsmaeder]

Theia seems to have no support for terminal profiles at all at the moment. Implementing the API correctly would also entail support for configuration in the preferences and a UI to select profiles.

[tsmaeder]

My plan of attack for this issue looks like this:

1. Introcuce a ProfileManagerService in the front end
2. Read the "legacy" preference values to add default profiles to the profile manager
3. Make TerminalService use the default profiles
4. Add schema info for terminal profiles in settings.json
5. Add code to merge profiles from setttings.json into the profile manager
6. Add UI to select profiles and default profiles when creating a terminal
7. Add API support for contributing profiles
8. Add support for contributes terminal profiles in package.json

Because we might want to declare VS Code 1.64.2 support (even if we lack full functionality), I'm starting with 1. and 8. and proceed from there.

[marcdumais-work]

@tsmaeder You can probably test using extension ms-vscode.js-debug, installable from the extensions view.

2022-12-16T16:45:06.372Z root ERROR [hosted-plugin: 1993873] Activating extension 'JavaScript Debugger' failed: TypeError: a.window.registerTerminalProfileProvider is not a function
at t.registerDebugTerminalUI (/tmp/vscode-unpacked/ms-vscode.js-debug-1.65.0.vsix/extension/src/extension.js:2:1279548)
at t.activate (/tmp/vscode-unpacked/ms-vscode.js-debug-1.65.0.vsix/extension/src/extension.js:2:1073785)
at PluginManagerExtImpl.startPlugin (/home/lmcmcds/theia/packages/plugin-ext/lib/plugin/plugin-manager.js:308:81)
at /home/lmcmcds/theia/packages/plugin-ext/lib/plugin/plugin-manager.js:218:32
at processTicksAndRejections (node:internal/process/task_queues:96:5)
at async PluginManagerExtImpl.$activatePlugin (/home/lmcmcds/theia/packages/plugin-ext/lib/plugin/plugin-manager.js:270:13)
at async Promise.all (index 0)
at async PluginManagerExtImpl.activateBySingleEvent (/home/lmcmcds/theia/packages/plugin-ext/lib/plugin/plugin-manager.js:265:9)
at async PluginManagerExtImpl.$activateByEvent (/home/lmcmcds/theia/packages/plugin-ext/lib/plugin/plugin-manager.js:249:13)
at async PluginManagerExtImpl.$start (/home/lmcmcds/theia/packages/plugin-ext/lib/plugin/plugin-manager.js:149:13)