sql: properly show values in type mismatch error

Currently, some values are displayed improperly in the type mismatch
error description. For VARBINARY, the word "varbinary" is printed
instead of the value. STRING values are printed without quotes, which
can be confusing in some cases, such as when it consists of spaces.

This patch introduces the following changes:
1) VARBINARY value will be printed as x'<value in hexadecimal format>'.
2) STRING value will be printed in single quotes.
3) UUID value will be printed in single quotes.

UUID value does not need to be enclosed in single quotes, since there
are no literals for UUIDs, but it looks more convenient.

Part of #6176