Semantic types pt 1 (special-type -> semantic-type rename) (#14780)

* Semantic types migration

* Fixup for basic querying

* Remove the relation type migration.

it makes the diff far too hard at the moment. need to be able to just
move everything from special_type -> semantic_type and then correct
the few that look at it to care about the effective type.

the PK/FK stuff gets really invasive and needs to be in its own much
smaller changeset

* Just rename special_type -> semantic_type for first change

* Special type -> semantic type

* special-type -> semantic-type

* SpecialType -> SemanticType

* special type -> semantic type

mostly in documentation, docstrings, etc

* Fix tests which relied on order of sets

database position was annotated by map-index'ing over the
set. changing `:special-type` to `:semantic-type` changed the order of
the seq produced from it.

* special -> semantic in schema_metadata

* Tim is awesome: Undo overeager special->semantic in docstrings

* Un-rename semantic_type in data_migrations

These migrations are run unless a migrations table marks them as
already having run. If they haven't run, then the db is older and the
column is special_type most likely. So we let them run as
`:special_type` and add some error handling to the migration runner
that is _opt in_.

```clojure
(defmigration ^{:author "camsaul", :added "0.20.0", :catch? true}
  migrate-field-types
  ...
  )

(try
  (@migration-var)
  (catch Exception e
    (if catch? ;; catch? from metadata
      (log/warn (format "Data migration %s failed: %s" migration-name (.getMessage e)))
      (throw e))))
```

* Fix merged master changes

just accepted their changes and fixed up rather than fix conflicts.