Remove dependency on CIO engine (#223)

<!-- Provide a brief summary of your changes -->
Replace the CIO dependency with only server/client core dependency.

## Motivation and Context
<!-- Why is this change needed? What problem does it solve? -->
In order to minimize the size of package. There are probably other
existing engines like Netty/Tomcat(server) or Java/OkHttp/Apache(client)
in the classpath. So we can reuse existing infrastructure.

## How Has This Been Tested?
<!-- Have you tested this in a real application? Which scenarios were
tested? -->
I have run:
- kotlin-sdk-client: jvmTest, jsTest
- kotlin-sdk-test: jvmTest, jsTest
- kotlin-sdk-server: allTests
- All `build` of samples

I have an issue about `samples/kotlin-mcp-server`.
`io.modelcontextprotocol` is not found in `commonMain`.

## Breaking Changes
<!-- Will users need to update their code or configurations? -->
Yes. They need to `implementation` CIO engine manually if they use it in
their app.

## Types of changes
<!-- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->
- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [x] Breaking change (fix or feature that would cause existing
functionality to change)
- [x] Documentation update

## Checklist
<!-- Go over all the following points, and put an `x` in all the boxes
that apply. -->
- [ ] I have read the [MCP
Documentation](https://modelcontextprotocol.io)
- [ ] 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
<!-- Add any other context, implementation notes, or design decisions
-->

closes https://github.com/modelcontextprotocol/kotlin-sdk/issues/111

---------

Co-authored-by: Konstantin Pavlov <1517853+kpavlov@users.noreply.github.com>

gradle/libs.versions.toml

@@ -39,10 +39,10 @@ kotlinx-collections-immutable = { group = "org.jetbrains.kotlinx", name = "kotli
 kotlin-logging = { group = "io.github.oshai", name = "kotlin-logging", version.ref = "logging" }
 
 # Ktor
-ktor-client-cio = { group = "io.ktor", name = "ktor-client-cio", version.ref = "ktor" }
+ktor-client-core = { group = "io.ktor", name = "ktor-client-core", version.ref = "ktor" }
 ktor-server-sse = { group = "io.ktor", name = "ktor-server-sse", version.ref = "ktor" }
 ktor-server-websockets = { group = "io.ktor", name = "ktor-server-websockets", version.ref = "ktor" }
-ktor-server-cio = { group = "io.ktor", name = "ktor-server-cio", version.ref = "ktor" }
+ktor-server-core = { group = "io.ktor", name = "ktor-server-core", version.ref = "ktor" }
 
 # Testing
 kotlinx-coroutines-test = { group = "org.jetbrains.kotlinx", name = "kotlinx-coroutines-test", version.ref = "coroutines" }
@@ -52,6 +52,8 @@ slf4j-simple = { group = "org.slf4j", name = "slf4j-simple", version.ref = "slf4
 kotest-assertions-json = { group = "io.kotest", name = "kotest-assertions-json", version.ref = "kotest" }
 
 # Samples
+ktor-client-cio = { group = "io.ktor", name = "ktor-client-cio", version.ref = "ktor" }
+ktor-server-cio = { group = "io.ktor", name = "ktor-server-cio", version.ref = "ktor" }
 mcp-kotlin = { group = "io.modelcontextprotocol", name = "kotlin-sdk", version.ref = "mcp-kotlin" }
 anthropic-java = { group = "com.anthropic", name = "anthropic-java", version.ref = "anthropic" }
 ktor-client-content-negotiation = { group = "io.ktor", name = "ktor-client-content-negotiation", version.ref = "ktor" }