Add Datamodel and Django Model definitions

[acwhite211]

Fixes #4358 and #2813

This PR adds datamodel and Django model code definitions, instead of relying on reading the 'specify_datamodel.xml' file from Specify 6. So, the schema is now statically defined in our python Django code, instead of dynamically be created at runtime. There is also code that can generated the static python code from the 'specify_datamodel.xml', so we can regenerate the code again in the future easily if we need to. Unit tests have been created to ensure the equivalence between the old and new datamodels. There was another branch django-schema that had a lot of code from the development process, but I cleaned it up and simplified it into this branch. There were some problems with adding the sql alchemy schema model classes, this isn't a pressing matter so this is something we can do in the future.

Checklist

• Self-review the PR after opening it to make sure the changes look good
  and self-explanatory (or properly documented)
• Add automated tests
• Add relevant issue to release milestone

Testing instructions

Unfortunately there isn't anything specific to test. I would say the best way to go about testing this from the UX side is to play around with forms and queries, and make sure no database table or field related errors occur. Also, for the sp7_only tables, test them out in the query builder.

sp7_only tables:

• Spuserexternalid
• Spattachmentdataset
• UniquenessRule
• UniquenessRule_Field
• Message
• Spmerging
• UserPolicy
• Role
• LibraryRole
• UserRole
• RolePolicy
• LibraryRolePolicy
• Spdataset

PR Testing Checklist:

• QB works on tables like Agent, Collecting Object, and Locality
• QB works on the new sp7_only tables
• The Database Schema page works without errors (UserTools->DatabaseSchema) localhost/specify/data-model

[lexiclevenger]

Testing instructions

Unfortunately there isn't anything specific to test. I would say the best way to go about testing this from the UX side is to play around with forms and queries, and make sure no database table or field related errors occur. Also, for the sp7_only tables, test them out in the query builder.

sp7_only tables:

• Spuserexternalid
• Spattachmentdataset
• UniquenessRule
• UniquenessRule_Field
• Message
• Spmerging
• UserPolicy
• Role
• LibraryRole
• UserRole
• RolePolicy
• LibraryRolePolicy
• Spdataset

PR Testing Checklist:

• QB works on tables like Agent, Collecting Object, and Locality
• QB works on the new sp7_only tables
• The Database Schema page works without errors (UserTools->DatabaseSchema) localhost/specify/data-model

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Trying to open results from queries for the new tables results in a 404 error:

Screen.Recording.2024-06-05.at.3.16.57.PM.mov

[realVinayak]

Feel free to shot it down. there is a discrepancy in how datamodel defines spappresourcedata. It is actually a BLOB but treated as a TextField in django, which required ugly workaround in record merging. Could you look at schema (in mariadb) and figure out more cases like that, and possibly resolve them?