Refactor BuiltInDataTypes

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This build of #27634 failed because I've added the UTF8 collation LATIN1_GENERAL_100_CI_AS_SC_UTF8 to BuiltInDataTypesSqlServerTest, but that only exists in SQL Server 2019. I think this means our Windows build uses an older SQL Server (note that the Helix build passed). Without the UTF8 collation the tests fail.

I can ignore the whole test suite unless SQL Server 2019 is available, but that's not ideal.

Note: we should consider refactoring the BuiltInDataTypes tests to have individual tests per data type (with theories). This would allow ignoring tests for specific types/scenarios (I have issues in Npgsql as well), and would make it easier to manage (updating all the parameter names when something is added is awful).

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Design discussion: skip BuiltInDataTypes when not on SQL Server 2019; we'll be upgrading our test infra to make sure we have 2019 everywhere at some point.

Repurposing this issue to track refactoring BuiltInDataTypes.

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I started introducing the type tests that should end up replacing BuiltInDataTypes, and adding coverage to them is tracked by #33521 - will close this as a dup of that.