Add workflow input handling and YAML support

[MDrakakis]

Updated GitHubActionsVS.csproj to include new source files: StringHelpers.cs, YamlHelpers.cs, InputMetadata.cs, and Workflow.cs. Added YamlDotNet package reference. Introduced WorkflowInputsDialog.xaml for user input and modified GHActionsToolWindow to integrate this dialog. Added utility classes for Base64 checking and YAML alias resolution. Enhanced input metadata representation and refactored code for improved readability and maintainability.

[MDrakakis]

This PR introduces one improvement based on Issue #23

Improvements

• Dynamic input dialog
• Workflow inputs are now generated directly from the YAML metadata.
• Default values and required flags are automatically applied.
• The dialog adapts to any workflow definition without requiring manual code changes.

Helpers

• Added YamlHelpers for unaliasing and safe key lookups.
• Added StringHelpers.IsBase64 for safe Base64 content detection.

Notes
This is a non-breaking change: existing workflows continue to run as before, but workflows with defined inputs now display a dynamic dialog for user input.

User Experience
When a user clicks Run Workflow, the following window is displayed to collect input values:

Example YAML Tested
Here’s an example workflow definition used for testing:

[timheuer]

thanks @MDrakakis -- acknowledging this PR -- gonna find some time to look at this and run it a bit. THanks for the screenshots of the change too.

[Copilot]

Pull Request Overview

This PR adds comprehensive workflow input handling and YAML support to the GitHub Actions Visual Studio extension. It introduces functionality to parse workflow YAML files, extract input definitions, and present a dialog for users to provide input values when running workflows.

Key changes:

• Added YAML parsing capabilities with YamlDotNet package integration
• Created workflow input dialog UI for user interaction when dispatching workflows
• Implemented helper classes for Base64 detection and YAML node manipulation

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
src/GitHubActionsVS.csproj	Added new source files and YamlDotNet package reference
src/UserControls/WorkflowInputsDialog.xaml	Dialog UI for collecting workflow input values from users
src/UserControls/WorkflowInputsDialog.xaml.cs	Dialog logic with dynamic control creation and validation
src/ToolWindows/GHActionsToolWindow.xaml.cs	Enhanced workflow dispatch with input parsing and dialog integration
src/ToolWindows/GHActionsToolWindow.xaml	Removed themed TreeView styles
src/Models/Workflow.cs	YAML deserialization models for workflow structure
src/Models/InputMetadata.cs	Input metadata representation and conversion logic
src/Helpers/YamlHelpers.cs	YAML node manipulation utilities
src/Helpers/StringHelpers.cs	Base64 validation utility

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[Copilot]

The numeric validation logic has several issues: it allows multiple decimal points (e.g., '1.2.3'), multiple minus signs anywhere in the string (e.g., '1-2-3'), and minus signs in invalid positions (e.g., '12-'). Consider using decimal.TryParse() or implementing proper position-based validation.

Suggested change

	foreach (char c in text)
	{
	if (!(char.IsDigit(c) || c == '-' || c == '.'))
	return false;
	}
	return true;
	decimal dummy;
	return decimal.TryParse(text, out dummy);

[Copilot]

The variable 'chosen' should be initialized as 'string.Empty' instead of 'null' to avoid potential null reference issues and maintain consistency with the rest of the codebase that uses string.Empty for empty strings.

Suggested change

	string chosen = null;
	string chosen = string.Empty;

[Copilot]

The Base64 decoding is not wrapped in a try-catch block. If the Base64 validation is incorrect or the string contains invalid Base64 characters, Convert.FromBase64String() will throw an exception, causing the workflow dispatch to fail.

Suggested change

	workflowContent = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(workflowContent));
	{
	try
	{
	workflowContent = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(workflowContent));
	}
	catch (FormatException ex)
	{
	await _pane.WriteLineAsync($"[{DateTime.UtcNow:o}] Error decoding workflow file content: {ex.Message}");
	workflowContent = null;
	}
	}

[Copilot]

The StringHelpers class should be declared as 'static' since all its methods are static. This prevents instantiation and makes the intent clearer.

Suggested change

	internal class StringHelpers
	internal static class StringHelpers

[Copilot]

[nitpick] Using 'null!' (null-forgiving operator) here is misleading since the method is designed to return false when no value is found. Consider using 'value = default!' or restructuring to avoid the null-forgiving operator.

Suggested change

	value = null!;
	value = default;