The logging is sometimes too verbose and uses inappropriate level. With this
change there should be less disturbing logs and less duplication.

Notable changes:

* `LifeCycleInitializer#handleException` - duplicated log, already handled in
  transports that use the initializer.
* `McpClientSession#sendRequest` - an MCP protocol level error in JSON-RPC is
  not really a reason for ERROR level log. Using INFO with more details.
* `DefaultJsonSchemaValidator` - ERROR logs in `validate` are always logged by
  the users of this method. `validateSchema` surfaces as
  `IllegalArgumentException` and can be logged at higher levels by the user.

Also: remove DEBUG logs from mcp-test module.

Signed-off-by: Dariusz Jędrzejczyk <2554306+chemicL@users.noreply.github.com>