What type of PR is this?

/kind task

What does this PR do / why do we need it:

1. Modified the config UI, make the connect charset configurable for user.
2. All supported character sets are configurale in UI and testcases are added.
3. Fix 2 small bugs in GetTypeInfo and SQLColumns

Which issue(s) this PR fixes:

Fixes #I1Q6NF:Support Configurable Charset to solve garbled result

Special notes for your reviewers:

charset properties file needs to be modified in openLooKeng ODBC gateway, and UTF16/32 will not be supported due to high impact.