vine: fixed_location task groups

[colinthomas-z80]

Proposed changes

This is an effort to detect groups of sequential, temp-file dependent tasks, and send them in batches to a single worker. Hopefully avoiding the overhead and complexity of maintaining fixed_location policy.

Post-change actions

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• make test Run local tests prior to pushing.
• make format Format source code to comply with lint policies. Note that some lint errors can only be resolved manually (e.g., Python)
• make lint Run lint on source code prior to pushing.
• Manual Update Did you update the manual to reflect your changes, if appropriate? This action should be done after your changes are approved but not merged.
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• PR RTM Mark your PR as ready to merge.

Additional comments

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[colinthomas-z80]

This currently works (from some testing i have done). It does some pretty expensive searches and is a bit invasive to the code. I wanted to open it up at this stage in case anyone has thoughts on the idea and implementation.