Fix: Escape in os.time was not working

[akeit0]

#227

[Copilot]

Pull request overview

This PR fixes a bug where escape sequences in os.date format strings were not being properly handled. The issue occurred when a % character wasn't followed by a recognized format specifier - the code failed to set the escape sequence flag, causing subsequent characters to be processed incorrectly.

Key changes:

• Added an else clause to properly set isEscapeSequence = true when % is encountered
• Added a test with FakeTimeProvider to verify the fix works correctly
• Added Microsoft.Extensions.TimeProvider.Testing package dependency for testing

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
tests/Lua.Tests/Lua.Tests.csproj	Added testing package dependency for time provider mocking
tests/Lua.Tests/DateTimeTests.cs	Added test case to verify date formatting with escape sequences
src/Lua/Standard/Internal/DateTimeHelper.cs	Fixed escape sequence handling logic in date formatting

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[Copilot]

The test name 'Test_LocalFunction_Nil_1' does not describe what is being tested. It should be renamed to something like 'Test_OsDate_FormatsDateTimeCorrectly' or 'Test_OsDate_EscapeSequenceHandling' to reflect that it's testing date formatting functionality.

Suggested change

	public async Task Test_LocalFunction_Nil_1()
	public async Task Test_OsDate_FormatsDateTimeCorrectly()