Add support for Composer in purl2url #203

Job	Run time
Lint & mypy	16s
Test & build (py3.12 on ubuntu-latest)	18s
Test & build (py3.11 on ubuntu-latest)	23s
Test & build (py3.10 on ubuntu-latest)	26s
Test & build (py3.9 on ubuntu-latest)	14s
Test & build (py3.8 on ubuntu-latest)	14s
Test & build (py3.7 on ubuntu-latest)	22s
Test & build (py3.12 on windows-latest)	50s
Test & build (py3.11 on windows-latest)	51s
Test & build (py3.10 on windows-latest)	49s
Test & build (py3.9 on windows-latest)	45s
Test & build (py3.8 on windows-latest)	54s
Test & build (py3.7 on windows-latest)	56s
Test & build (py3.12 on macos-latest)	19s
Test & build (py3.11 on macos-latest)	20s
Test & build (py3.10 on macos-latest)	18s
Test & build (py3.9 on macos-latest)	18s
Test & build (py3.8 on macos-latest)	26s
Test & build (py3.7 on macos-latest)	36s
	9m 35s

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