Use max length/no collation TStrings for parameter arguments

Instead of VARCHAR(255) UTF8 UCS_BINARY, which truncates and collates incorrectly.

This is a wider change than just for TLike but I believe this is always the behavior we want, similar to the cast related change in #1305.

If we wanted to be more conservative, something (probably TPickingNormalizer) would need to receive the unresolved instances to be able to intervene for only parameters.


Would you mind making `inputTpv.isNullable()` be `true`? I find that a clearer indication that the input is giving no help in forming the type.