chore: relax Detekt rules for tests (#582)

- Updated `detekt.yml` to exclude test folders from
`EmptyFunctionBlock`, `LargeClass`, and `LongMethod` checks.
- Cleanup detekt-baseline files.
- Simplified `.idea/detekt.xml`.

## Motivation and Context
To reduce linter noise and reduce tension

## How Has This Been Tested?
`./gradlew detekt`

## Breaking Changes
No

## Types of changes
- [x] Build tool/ci update

## Checklist
<!-- Go over all the following points, and put an `x` in all the boxes
that apply. -->
- [x] I have read the [MCP
Documentation](https://modelcontextprotocol.io)
- [x] My code follows the repository's style guidelines
- [x] New and existing tests pass locally
- [ ] I have added appropriate error handling
- [ ] I have added or updated documentation as needed

## Additional context

#567

kotlin-sdk-client/detekt-baseline-commonTestSourceSet.xml

@@ -2,7 +2,6 @@
 <SmellBaseline>
   <ManuallySuppressedIssues/>
   <CurrentIssues>
-    <ID>LongMethod:StreamableHttpClientTransportTest.kt:StreamableHttpClientTransportTest$@Ignore @Test fun testNotificationSchemaE2E</ID>
     <ID>MaxLineLength:StreamableHttpClientTransportTest.kt:StreamableHttpClientTransportTest$"""data: {"jsonrpc":"2.0","method":"notifications/progress","params":{"progressToken":"upload-123","progress":50,"total":100}}"""</ID>
     <ID>MaxLineLength:StreamableHttpClientTransportTest.kt:StreamableHttpClientTransportTest$"""data: {"jsonrpc":"2.0","method":"notifications/resumed","params":{"fromToken":"$lastEventIdSent"}}"""</ID>
   </CurrentIssues>