optimize: optimize database driver cannot found message(#6760)

[lyl2008dsg]

• I have registered the PR changes.

Ⅰ. Describe what this PR did

This PR resolves the issue of the MySQL driver not loading when starting the apache/seata-server:2.1.0.jre17 Docker image. The fix involves removing the custom classloader setup and relying on the default classloader to handle the MySQL driver loading. Additionally, the MySQL driver jar has been moved from the lib/jdbc directory to the lib directory, simplifying the path and ensuring the driver is loaded properly.

Ⅱ. Does this pull request fix one issue?

fixes #6760

Ⅲ. Why don't you add test cases (unit test/integration test)?

The changes made pertain to configuration and environment setup, which are typically validated through deployment tests rather than unit or integration tests. Future contributions could focus on creating automated tests for Docker image configurations to ensure environment consistency.

Ⅳ. Describe how to verify it

To verify this fix:

1. Ensure the MySQL driver jar is now located in the lib directory.
2. Start the Seata server using the updated configuration.
3. Check that the MySQL driver is loaded correctly without any errors during the initialization process.
4. Optionally, connect to a MySQL database to confirm that database connectivity is functioning correctly.
5. Additionally, Perform a build using the specific Maven profile:
   • Run mvn clean install -P release-seata to build the project.
   • Navigate to incubator-seata/distribution/target/apache-seata-x.x.x-incubating-bin/apache-seata/bin and execute seata-server.sh.
   • Ensure the application starts up correctly, referring to the application.yml settings for seata.config.type: file, and check the logs to verify that the store.db.driverClassName = com.mysql.cj.jdbc.Driver setting from file.conf is correctly utilized.

Ⅴ. Special notes for reviews

Please focus on the changes made to the classloader behavior and the repositioning of the MySQL driver jar. Confirm that these changes align with best practices for Docker and Java application deployments. Additionally, verify that the removal of custom classloader settings does not inadvertently affect other aspects of the system's behavior.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 52.19%. Comparing base (3bb8f73) to head (0d61467).

Additional details and impacted files

@@            Coverage Diff            @@
##                2.x    #6791   +/-   ##
=========================================
  Coverage     52.18%   52.19%           
- Complexity     6311     6312    +1     
=========================================
  Files          1067     1067           
  Lines         37278    37278           
  Branches       4427     4427           
=========================================
+ Hits          19455    19457    +2     
+ Misses        15890    15889    -1     
+ Partials       1933     1932    -1     

Files with missing lines	Coverage Δ
...eata/core/store/db/AbstractDataSourceProvider.java	0.00% <ø> (ø)

... and 1 file with indirect coverage changes

[funky-eyes]

Suggested change

	- [[#6760](https://github.com/apache/incubator-seata/pull/6765)] fix MySQL driver loading by replacing custom classloader with system classloader for better compatibility and simplified process
	- [[#6765](https://github.com/apache/incubator-seata/pull/6765)] fix MySQL driver loading by replacing custom classloader with system classloader for better compatibility and simplified process

[funky-eyes]

Suggested change

	- [[#6760](https://github.com/apache/incubator-seata/pull/6791)] make exception message generic for all database drivers
	- [[#6791](https://github.com/apache/incubator-seata/pull/6791)] make exception message generic for all database drivers