Test TextSearchComplete

[roblourens]

#55790

Implement a TextSearchProvider. See that a provider can now optionally return a TextSearchComplete object with a limitHit flag, which the provider can use to signal that it hit an internal result maximum. When the flag is set, the yellow warning on the search view should be shown after the search, no matter how many results were actually returned.

https://github.com/Microsoft/vscode/blob/master/src/vs/vscode.proposed.d.ts#L145

Complexity: 3

• AnyOS @aeschli
• AnyOS @mjbvz