Provide dedicate test suite for connector testing

[kokosing]

Currently we have are using two tests suites: AbtractTestDistributedQueries and AbstractTestIntegrationSmokeTest. Where each connector implements them both of and also add more connector specifics tests to either one of these or to separate. This has following issues:

• If one adds a test is not clear where to put the test.
• It is difficult to add a new generic tests dedicated only for connectors.

Solution for this is to merge two test classes above into one and create one common base test class for connector testing.

• Add dedicated test for queries with caching Add dedicated test for queries with caching #6986
• Introduce BaseConnectorTest, merging AbstractTestDistributedQueries and AbstractTestIntegrationSmokeTest Introduce BaseConnectorTest, merging AbstractTestDistributedQueries and AbstractTestIntegrationSmokeTest #6989
• Make sure that tests added to deprecated tests are also added to BaseConnectorTest Verify that BaseConnectorTest contains all tests #6999
• Migrate PostgreSQL tests Introduce BaseConnectorTest, merging AbstractTestDistributedQueries and AbstractTestIntegrationSmokeTest #6989
• Migrate Redis tests Introduce BaseConnectorTest, merging AbstractTestDistributedQueries and AbstractTestIntegrationSmokeTest #6989
• Migrate MySQL tests
• Migrate MemSQL tests
• Migrate SQL Server tests
• ...

CC: @trinodb/maintainers

[kokosing]

One issue of this idea is the need of the migration of all connector tests to this new framework.