Fix #348: Allow ToolError to carry custom content and is_error #2326

Job	Run time
checks / readme-snippets	12s
checks / pre-commit	20s
checks / test (3.12, lowest-direct, windows-latest)	4m 21s
checks / test (3.11, locked, ubuntu-latest)	50s
checks / test (3.11, lowest-direct, ubuntu-latest)	46s
checks / test (3.10, locked, windows-latest)	2m 49s
checks / test (3.11, locked, windows-latest)	2m 36s
checks / test (3.10, locked, ubuntu-latest)	51s
checks / test (3.13, lowest-direct, ubuntu-latest)	48s
checks / test (3.13, locked, ubuntu-latest)	47s
checks / test (3.13, lowest-direct, windows-latest)	2m 50s
checks / test (3.12, locked, ubuntu-latest)	53s
checks / test (3.14, locked, ubuntu-latest)	2m 23s
checks / test (3.12, locked, windows-latest)	3m 53s
checks / test (3.14, lowest-direct, ubuntu-latest)	1m 13s
checks / test (3.10, lowest-direct, ubuntu-latest)	49s
checks / test (3.11, lowest-direct, windows-latest)	2m 53s
checks / test (3.13, locked, windows-latest)	2m 55s
checks / test (3.12, lowest-direct, ubuntu-latest)	59s
checks / test (3.10, lowest-direct, windows-latest)	2m 41s
checks / test (3.14, lowest-direct, windows-latest)	2m 27s
checks / test (3.14, locked, windows-latest)	3m 41s
all-green	5s
	42m 2s

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