[v0.13] Backport to accept Legolas metadata

[ericphanson]

This PR is to the release-v0.13 branch (introduced recently for #105) and allows tables written by Onda v0.14 to be read on Onda v0.13. Ideally consumers can just update to Onda v0.14, but that can be tricky when it is a deep dependency (so might require releases of many packages), so this should help ease the transition (since compat won't prevent patch updates, so you only need to update the patch of your current project rather than compat bounds everywhere in the stack-- though we should do that too 😄).

[kleinschmidt]

are we sure this won't mess with the YAML parsers ;;;;)))))

[jrevels]

Hmm...

valid signal/annotation tables in Onda v0.14 are a superset of the tables that are valid in Onda v0.13 IIRC because Onda v0.14 drops the column ordering requirement

So you could have a valid Onda v0.14 table that this PR allows the user to load in v0.13, but then errors when validated (e.g. naive calls to read_annotations or read_signals could break unless you pass validate_schema=false). unfortunately, I don't think this is unlikely since column ordering isn't a concern/guarantee in Legolas land.

Maybe it'd be easy to change e.g. validate_annotation_schema/validate_signal_schema so that column ordering is only "soft" validated, e.g. raises a warning instead of exception if things aren't as expected?

otherwise this LGTM 👍

[kleinschmidt]

is this still worth doing @ericphanson ?

[ericphanson]

Uhh, I don't totally remember the context but if we still need this then I can try to implement Jarrett's suggestion and proceed with a backport release.