Add support for "workspaces" based on window names

[zadjii-msft]

This adds a new feature to the Windows Terminal: "Workspaces"

Workspaces are very shamelessly inspired by Edge workspaces of the same name.

wt-workspaces-000.mp4

The core idea is that when users name a window and they close that window, we will persist that Windows layout and buffers, seperately from the rest of window restoration. So a user can open a named window, open some profiles, some panes, do some stuff in it, then close it, and we will keep that state around for the next time the user opens that window name.

Unnamed windows still behave the same. If you close an unnamed window, and it's not the last window, then we won't persist the state of it.

To facilitate restoring named windows, we add a openWorkspace action. This allows us to persist the open workspace action in the window layout restoration path. So when we deserialize the list of tab layouts, and open workspace action will tell us, hey, go retrieve this known workspace from the state.json, instead of trying to serialize the window state in two places.

state.json

	"persistedWindowLayouts" :
	[
		{
			"initialPosition" : "910,462",
			"initialSize" :
			{
				"height" : 623.20001220703125,
				"width" : 934.4000244140625
			},
			"launchMode" : "default",
			"tabLayout" :
			[
				{
					"action" : "newTab",
					"commandline" : "\"C:\\Program Files\\PowerShell\\7\\pwsh.exe\"",
					"profile" : "{574e775e-4f2a-5b96-ac1e-a2962a402336}",
					"sessionId" : "{09d3ef05-ba3d-44ed-a8f1-065d08a806a4}",
					"startingDirectory" : "C:\\Users\\zadji",
					"suppressApplicationTitle" : false,
					"tabTitle" : "PowerShell"
				},
			]
		},
		{
			"tabLayout" :
			[
				{
					"action" : "openWorkspace",
					"name" : "wsl"
				}
			]
		}
	],
	"persistedWorkspaces" :
	{
		"wsl" :
		{
			"initialPosition" : "109,502",
			"initialSize" :
			{
				"height" : 568,
				"width" : 1184.800048828125
			},
			"launchMode" : "default",
			"tabLayout" :
			[
				{
					"action" : "newTab",
					"commandline" : "ubuntu.exe",
					"profile" : "{51855cb2-8cce-5362-8f54-464b92b32386}",
					"sessionId" : "{a7f70c49-71ec-4ac4-9f3a-4884528a3fd6}",
					"startingDirectory" : null,
					"suppressApplicationTitle" : false,
					"tabTitle" : "Ubuntu"
				},
				{
					"action" : "renameWindow",
					"name" : "wsl"
				}
			]
		}
	},

As demoed in the video, we add a flyout to list the windows that the user has open, and the named workspaces that they have saved. This allows users to quickly reopen previously closed workspaces, as well as quickly rename a window, thereby adding it to the list of saved workspaces. This button can also be hidden using the theme settings.

Closes #17084

[carlos-zamora]

MG edit: collapsing these todos, as they should all be addressed in the most recent push

Feedback from Bug Bash (5/5)

• Ctrl+Shift+W on a workspace (named) window will crash the app
• how do i delete a workspace? closing the last tab manually didn't do it...
• window renamer should automatically take focus
• nit: add "workspaces" action(s) to make it keyboard accessible
• Small text: Great! Small button: Eh? Makes it hard to press quickly.
• Asymmetric button alignment:

Personal note: this is a really cool feature. Thanks for making it happen 😊

There was also some discussion as to how to manage workspaces. It should probably go in the settings UI. Looks like management is pretty simple though. We'd really just need the ability to rename, delete, and open them.