JDBC custom connection support

[clach04]

Similar to ODBC custom connection options, required for SSO/FIM as well as other user options like custom initial SQL (ala ING_SET / start.sql - internal ref II-9616)

• 4b3cc53 - actual change
• a09285f - doc change

See code links in #34 (comment)

NOTE need to update https://github.com/ActianCorp/actian_tableau_connector/blob/master/README_DEV.md#install-drivers about "preferred" connector.

Extracted notes from #27

NOTE on JDBC requirement since 2022-04-01

• https://tableau.github.io/connector-plugin-sdk/docs/gallery-submission#step-1-build-and-test-your-connector
  • raw code for above docs https://github.com/tableau/connector-plugin-sdk/blob/gh-pages/docs/gallery-submission.md
  • JDBC requirement change Mar 31, 2022 tableau/connector-plugin-sdk@88f9cd7

[clach04]

@hab6 if we have to do a new hand over of the taco for approval, we should prioritize this enhancement.