Replaced the using directive for InvokeAction with Action in InvokeActionTests.cs to reflect recent namespace reorganization. No other changes were made.
Introduce InvokeActionTests.cs with comprehensive tests for:
- Placeholder replacement logic (ReplacePlaceholders) across int, bool, string, DateTime, DateTimeOffset types, multiple placeholders, and various prefix formats.
- Value extraction by column name (GetValueByColumnName), including models with and without [Column] attributes.
- Exception handling for unresolvable placeholders and invalid input scenarios.
These tests ensure robust coverage of both normal and error cases.
