Add "meta" block to all content schemas, including non-multi-company-reviewed

At the time this issue is created, some content schemas have been upgraded to handle units of measure via the meta block; Others have retained on older way of identifying the UoM explicitly. This issue is to complete the upgrade (started by #436 (closed) ) of all content schemas, to included the meta block, even if the older schemas have not yet been further multi-company-reviewed.

Actions needed:

1. Mike Jones will list the content schemas that are in a "half-baked state" (that have some but not all multi-company review)
   1. Per Mike, exclude these:
      1. extraction
      2. water_analysis
      3. bulk_pyrolysis (probably)
   2. That's it: these 3
2. Edgar will run the "meta-block" "model generator" script on all other non-company-review schemas (in other words, excluding those listed by Mike) (You can identify non-company-review schema from this page; Items with an "N" in the multi-company-review column.)
3. Mike and Daniel will find the appropriate historic version of the content schema proposal spreadsheet (for the schemas listed above) that does not have any multi-company review comments/changes, and provide those to Edgar
4. Edgar will run the "meta-block" "model generator" script on this set of schemas as well
5. In parallel: As needed Edgar will ask Mike & Daniel to update the proposal spreadsheet with regard to any errors found, such as wrong data types assigned to attributes (which don't match the examples)