Add support for Int128, UInt128

[bgrainger]

MySQL Server does not support 128-bit integers, but it seems useful to support the Int128 and UInt128 types for MySqlParameter.Value, MySqlDataReader.GetFieldValue<T>, and other places values can be passed to/from the database. (Any values larger than the range of a 64-bit integer would be checked by the database and cause a server-side error; no restrictions should be placed on the client side.)

[bgrainger]

Related issues:

• Consider mapping Int128/UInt128 to pg numeric npgsql/npgsql#5075
• Microsoft.Data.Sqlite: Support BigInteger, Int128 & UInt128 dotnet/efcore#30930
• Map Int128/UInt128 where possible dotnet/efcore#28498