feat(findWorkspaceDir): configurable strategy

[pi0]

Context: Discussions in #218

This allows configurable strategy for findWorkspaceDir

• Options keys workspaceFile, gitConfig, lockfile and packageJSON can be set to false to skip test or closest | furthest for different strategy
• Default testing order can be overridden with tests: [] (same keys in array which also gives alternative DX to disable/opt-in)

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(unrelated): we might extract this is as generic "detector" utility with multi checkers