chore: update atlas tools output to json - MCP-264

[blva]

Proposed changes

• updates the atlas tool responses to return json instead of tables

Checklist

• I have signed the MongoDB CLA

[coveralls]

Pull Request Test Coverage Report for Build 18911327516

Details

• 37 of 60 (61.67%) changed or added relevant lines in 6 files are covered.
• 2 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+0.09%) to 80.317%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/tools/atlas/read/listDBUsers.ts	16	18	88.89%
src/tools/atlas/read/listClusters.ts	1	10	10.0%
src/tools/atlas/read/listAlerts.ts	0	12	0.0%

Files with Coverage Reduction	New Missed Lines	%
src/tools/atlas/read/listAlerts.ts	1	65.12%
src/tools/atlas/read/listClusters.ts	1	60.64%

Totals
Change from base Build 18909867313:	0.09%
Covered Lines:	6343
Relevant Lines:	7762

---

💛 - Coveralls

[Copilot]

Pull Request Overview

This PR updates Atlas tools to return JSON-formatted data instead of table-formatted output, improving machine readability and consistency.

Key Changes:

• Replaced table-formatted output with JSON.stringify() for all Atlas tool responses
• Updated integration tests to validate JSON content instead of parsing tables
• Removed unused table parsing utility function

Reviewed Changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/tools/atlas/read/listOrgs.ts	Converts organization list output from table to JSON format
src/tools/atlas/read/listDBUsers.ts	Converts database users output from table to JSON, removes helper functions
src/tools/atlas/read/listClusters.ts	Converts cluster list output from table to JSON for both all-projects and single-project views
src/tools/atlas/read/listAlerts.ts	Converts alerts output from table to JSON format
src/tools/atlas/read/inspectCluster.ts	Converts cluster details output from table to JSON format
src/tools/atlas/read/inspectAccessList.ts	Converts access list entries output from table to JSON format
tests/integration/tools/atlas/orgs.test.ts	Updates test to validate JSON content instead of parsing tables
tests/integration/tools/atlas/clusters.test.ts	Updates tests to validate JSON content, removes table parsing logic
tests/integration/tools/atlas/alerts.test.ts	Updates test description and assertions to expect JSON format
tests/integration/tools/atlas/atlasHelpers.ts	Removes unused parseTable helper function