Validate JDBC params in `check` operation

[grishick]

Tell us about the problem you're trying to solve

Currently, we allow users to enter additional JDBC parameters in free form. If the parameters are entered incorrectly, the connection will fail. If user enters any of the parameters that the connector specifies internally (such as SSH-related parameters), the parameters will end up duplicated in the URL causing non-deterministic behavior.

Describe the solution you’d like

• Validate parameter format (key1=value1&key2=value2) in check method
• fail check method if user specifies any of the parameters that the connector uses internally

[tuliren]

Context

Currently on the destination database connector side, we do check custom JDBC parameters in the check command. This is done as follows:

1. Helper method JdbcUtils#parseJdbcParameters takes in the free-form user input, and return a string to string map.
2. AbstractJdbcDestination#getDefaultConnectionProperties returns the JDBC parameters that are set with default values. These values should not be overridden by users.
3. The user parameters from step 1 and default parameters from step 2 are combined in AbstractJdbcDestination#getConnectionProperties. This method verifies that no default parameter is overridden by the user.

Candidate solution

Copy the same solution to the source database connector side. For sources that support custom JDBC parameters, the abstract JDBC source class can 1) use the same JdbcUtils#parseJdbcParameters helper method to parse user input, 2) have an abstract method to allow each connector to specify default parameters, and 3) merge user inputs with default parameters.

Expected outcome

The check should throw exception when

• The user input is not a valid string for JDBC parameters.
• The user input overrides a default parameter.

[ryankfu]

The validation logic has been added into master #14586