Remove model resource and all supporting code
merge nathanlws: Remove model resource and all supporting code

Merge pull request #1125 from nathanlws/sql-layer/remove-model-resource
https://github.com/FoundationDB/sql-layer/pull/1125
Make sure collation is included in translated type.
New definitions of typed AIS objects.
Update callers for new APIs.
Add a somewhat more compatible way of displaying type description.
Similarly update tests.
Remove validation for types being static and associated internal error.
A few leftover importers of types.
Get rid of charset & collation object and its interning.
Remove the rest of the Type(s) class.
Bring back validation, but in a separate class now.
Update tests. Mostly formatting changes due to few type objects.
Standardize more on charset / collation ids than names, since that's what TInstance does. The names are for externalization.
Update tests.
Need to allow more join types. Widest of most ints is BIGINT, but of BIGINT itself it's DECIMAL.
Keep TIMESTAMP meaning DATETIME for now, as before.