refactor: `McpError` renamed to `MCPError` and flatten parameters #375

Job	Run time
checks / pre-commit	33s
checks / readme-snippets	12s
checks / test (3.11, lowest-direct, ubuntu-latest)	53s
checks / test (3.10, lowest-direct, ubuntu-latest)	55s
checks / test (3.11, lowest-direct, windows-latest)	2m 39s
checks / test (3.10, lowest-direct, windows-latest)	2m 52s
checks / test (3.12, lowest-direct, windows-latest)	3m 31s
checks / test (3.14, lowest-direct, ubuntu-latest)	1m 15s
checks / test (3.10, locked, windows-latest)	2m 21s
checks / test (3.11, locked, windows-latest)	2m 28s
checks / test (3.12, lowest-direct, ubuntu-latest)	56s
checks / test (3.10, locked, ubuntu-latest)	49s
checks / test (3.12, locked, windows-latest)	3m 24s
checks / test (3.11, locked, ubuntu-latest)	46s
checks / test (3.13, lowest-direct, ubuntu-latest)	51s
checks / test (3.13, lowest-direct, windows-latest)	2m 53s
checks / test (3.13, locked, ubuntu-latest)	44s
checks / test (3.12, locked, ubuntu-latest)	56s
checks / test (3.13, locked, windows-latest)	2m 19s
checks / test (3.14, locked, windows-latest)	3m 55s
checks / test (3.14, lowest-direct, windows-latest)	2m 28s
checks / test (3.14, locked, ubuntu-latest)	2m 17s
all-green	2s
	39m 59s

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