Add stored procedure and function tools with comprehensive test coverage

[shubham070]

🚀 Overview

This PR implements comprehensive support for SQL Server stored procedures and functions in the MCP server, including execution capabilities, metadata retrieval, and robust test coverage.

✨ Features Added

New MCP Tools (6 tools)

• ExecuteStoredProcedure - Execute stored procedures with optional parameters
• ExecuteFunction - Execute table-valued functions with optional parameters
• ListProceduresAndFunctions - List all stored procedures and functions in the database
• DescribeProcedureOrFunction - Get detailed metadata about specific procedures/functions
• CreateProcedure - Creates a new stored procedure in the SQL Database
• CreateFunction - -"Creates a new function in the SQL Database

Comprehensive Test Coverage

• 18 Unit Tests - Fast, isolated tests without database dependencies
• Integration Tests - End-to-end testing with real SQL Server (existing tests preserved)
• Test Documentation - Complete README with best practices and execution commands

🔧 Technical Implementation

Core Features

• Parameter validation and sanitization for security
• Support for both parameterized and parameterless execution
• Comprehensive error handling and logging
• Consistent return format following existing MCP patterns
• Full metadata extraction including parameter definitions

Architecture Improvements

• Clean separation between unit and integration tests
• Follows Test Pyramid principle for optimal feedback cycles
• Maintains existing code patterns and conventions
• Zero breaking changes to existing functionality

🧪 Testing Strategy

Unit Tests (ToolsUnitTests.cs)

dotnet test --filter "FullyQualifiedName~ToolsUnitTests"
# ✅ 16 tests, ~1.2s execution time, no database required