Fix indentation rules for VB

[dmitrivMS]

Fixes #118932

Added more tests as well to cover onEnter scenarios.

[Copilot]

Pull request overview

This PR fixes Visual Basic indentation issues by refining the indent/dedent patterns and adding explicit onEnter rules. The changes ensure proper automatic indentation when typing block keywords (like Sub, Module, If...Then) and dedenting when typing block terminators (like End Sub, End If, Loop).

Key changes:

• Updated increaseIndentPattern regex to properly handle If/ElseIf...Then statements and ensure both alternatives are correctly anchored
• Added vbOnEnterRules to prevent unintended indentation after End statements and block terminators
• Removed overly broad onEnterRule that was incorrectly preventing indentation after lines ending with parentheses
• Added comprehensive test coverage for Module, Sub, Function, Class, If/ElseIf/Else, While, For, Do/Loop, Select/Case, and Try/Catch/Finally blocks

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
src/vs/editor/test/common/modes/supports/onEnterRules.ts	Exports new vbOnEnterRules array with pattern to prevent indentation after block terminators
src/vs/editor/test/common/modes/supports/indentationRules.ts	Refactors increaseIndentPattern for VB to properly group alternatives and fix negative lookahead for single-line constructs
src/vs/editor/contrib/indentation/test/browser/indentation.test.ts	Imports vbOnEnterRules, registers it for VB language, and adds 18 new test cases covering various indentation scenarios
extensions/vb/language-configuration.json	Updates indentation patterns to match test configuration and removes problematic onEnterRule for closing parentheses