Git drop stash commands should use modal dialog (microsoft#166573)

Since the warning is initiated through user action, and the user is required to interact with the warning to finish their intended action we should use a modal dialog here.

Author: alexr00

extensions/git/src/commands.ts

@@ -3017,6 +3017,7 @@ export class CommandCenter {
 		const yes = l10n.t('Yes');
 		const result = await window.showWarningMessage(
 			l10n.t('Are you sure you want to drop the stash: {0}?', stash.description),
+			{ modal: true },
 			yes
 		);
 		if (result !== yes) {
@@ -3041,7 +3042,7 @@ export class CommandCenter {
 			l10n.t('Are you sure you want to drop ALL stashes? There is 1 stash that will be subject to pruning, and MAY BE IMPOSSIBLE TO RECOVER.') :
 			l10n.t('Are you sure you want to drop ALL stashes? There are {0} stashes that will be subject to pruning, and MAY BE IMPOSSIBLE TO RECOVER.', stashes.length);
 
-		const result = await window.showWarningMessage(question, yes);
+		const result = await window.showWarningMessage(question, { modal: true }, yes);
 		if (result !== yes) {
 			return;
 		}