feat: add search tool to mcp

[yelizhenden-mdb]

Proposed changes

Jira ticket: CLOUDP-393141

This PR adds a search tool to the MCP server that enables regex-based search across OpenAPI specifications.It allows searching with the following features:

• Regex pattern matching - Search using regular expressions (case-sensitive or case-insensitive)
• Multi-category search - Search across 6 categories: operations, schemas, parameters, responses, tags, and paths
• Flexible filtering - Optionally limit search to specific categories
• Match context - Returns which fields matched (matchedIn) and the matched text
• Pagination - Configurable result limits with metadata showing total matches and available results per category

What Gets Searched

Operations

• operationId: The unique identifier for the operation
• summary: Brief description of the operation
• description: Detailed description of the operation
• tags: Tags associated with the operation

Schemas

• name: Schema name
• description: Schema description
• properties: Property names within the schema

Parameters

• name: Parameter name
• description: Parameter description

Responses

• name: Response name
• description: Response description

Tags

• name: Tag name
• description: Tag description

Paths

• path: The path pattern itself (e.g., /users/{userId})

Checklist

• I have signed the MongoDB CLA
• I have added tests that prove my fix is effective or that my feature works

Changes to Spectral

• I have read the README file for Spectral Updates

Further comments

[andmatei]

LGTM

[andmatei]

[nit] Since this description will be used by the agent I think it might be a good idea to add what the agent can search against (operation, tags etc.)

[yelizhenden-mdb]

I added more detailed descriptions for all the tools implemented until now. Feel free to take a second look!