Post-merge curation of COVID transmission site terminology

[pbuttigieg]

With reference to #1166 #1105

We're merging these in for expediency as they're part of a COVID text-mining project.
However, there are several terms that need additional curation post hoc.

@ddooley has confirmed that synonym type changes, rearrangements in the hierarchies, modifications to textual and axiomatic defs, and modifications to labels providing the original label is added as a synonym (any type), will not affect their downstream uses.

The terms to curate are in the range:
ENVO:03501102 - 03501355

Note: this range also includes terms for food processing sites belonging to the MIxS food extension.