Add interface for adding value selection in QuickInput for extension API

[CrafterKolyan]

Fixes #233274

Adding interface to setValueSelection in QuickInput for extensions.
I am also fine with creating property valueSelection like this:

vscode/src/vscode-dts/vscode.d.ts

Lines 12828 to 12837 in 818169a

	/**
	* Selection range in the input value. Defined as tuple of two number where the
	* first is the inclusive start index and the second the exclusive end index. When `undefined` the whole
	* pre-filled value will be selected, when empty (start equals end) only the cursor will be set,
	* otherwise the defined range will be selected.
	*
	* This property does not get updated when the user types or makes a selection,
	* but it can be updated by the extension.
	*/
	valueSelection: readonly [number, number] | undefined;

though it looks to me that having a functon setValueSelection explicitly documents the fact that you can't read valueSelection property for the current user selection.

The best implementation in my opinion should be valueSelection property that is also updated with user selection, though for my use case just setValueSelection works. Ready to reimplement it to any of these two cases.

Will probably change it to valueSelection any way as I think that means literally zero code from my side apart from exposing the already existing API.

[TylerLeonhardt]

We should have this be a property valueSelection to be aligned with the InputBox equivalent.

Keep in mind, since this requires API proposal, we will discuss this internally. However, this feels small and provides value so I think this will be a good addition.

[CrafterKolyan]

Sure, no problem discussing this. I changed the interface.

To be honest I feel that this should be the property of QuickInput (which is more general and this is where value comes from) rather than of InputBox or QuickPick.

Also sorry for accidentally closing the PR, I accidentally force-pushed this branch to the current main and it automatically closed the PR.

[TylerLeonhardt]

Yes, I think on QuickInput would be ideal. Your PR could just add valueSelection to QuickInput in a proposed API, and then when it's finalized we can remove it from InputBox`

[CrafterKolyan]

Sure, I've changed this to have valueSelection on QuickInput