Introduce a `ServerSession` to manage multiple connections to the mcp
server. `Protocall` logic of the `Server` was moved to `ServerSession`,
while MCP resources logic remained in `Server`
## Motivation and Context
1. Fix the multiple connection issues reported for SSE transport
2. Avoid server duplications during configurations: currently every connection
creates a session, but the server stays single
## How Has This Been Tested?
Added `SseIntegrationTest` and `WebSocketIntegrationTest` integration
tests to check connection with single and multiple clients
## Breaking Changes
This change caused several depreciations:
1. The `Server` -> `Protocol` inheritance (which caused single
connection issue) should be removed in future releases, now, all the
methods inherited from `Protocall` marked as `Deprecated` with a
`Warning`
2. Websocket Ktor server initialization changes in order not to create
server instance per connection
## Types of changes
- [ ] Bug fix (non-breaking change which fixes an issue)
- [x] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation 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
- [x] I have added appropriate error handling
- [x] I have added or updated documentation as needed
## Additional context
<!-- Add any other context, implementation notes, or design decisions
-->
---------
Co-authored-by: devcrocod <devcrocod@gmail.com>
d86813636e