Consolidate McpClientException/McpServerException into McpException #461

Job	Run time
build (macos-latest, Release)	58s
build (windows-latest, Release)	5m 22s
build (windows-latest, Debug)	7m 12s
build (ubuntu-latest, Release)	3m 26s
build (ubuntu-latest, Debug)	1m 59s
build (macos-latest, Debug)	1m 2s
publish-coverage / publish-coverage	35s
	20m 34s

Provide feedback