[Improve][Connector-V2] Optimize dialect selection in jdbc

[corgy-w]

Purpose of this pull request

Does this PR introduce any user-facing change?

How was this patch tested?

Check list

• If any new Jar binary package adding in your PR, please add License Notice according
  New License Guide
• If necessary, please update the documentation to describe the new feature. https://github.com/apache/seatunnel/tree/dev/docs
• If you are contributing the connector code, please check that the following files are updated:
  1. Update plugin-mapping.properties and add new connector information in it
  2. Update the pom file of seatunnel-dist
  3. Add ci label in label-scope-conf
  4. Add e2e testcase in seatunnel-e2e
  5. Update connector plugin_config
• Update the release-note.

[hailin0]

waiting ci passed

[Copilot]

Pull Request Overview

This PR optimizes JDBC dialect selection by introducing a dedicated dialect configuration that takes precedence over URL inspection. Key changes include:

• Adding a new method (dialectFactoryName) across various dialect factory classes.
• Enhancing JdbcDialectLoader to select the appropriate dialect based on an explicit configuration.
• Updating configuration classes and documentation to support the new dialect option.

Reviewed Changes

Copilot reviewed 40 out of 40 changed files in this pull request and generated 1 comment.

File	Description
connector-jdbc/internal/dialect/*	Adds the dialectFactoryName() method to all dialect factories, returning the corresponding identifier from DatabaseIdentifier.
JdbcDialectLoader.java	Overloads and adjusts the load() method to allow explicit selection via a new dialect parameter.
JdbcOptions.java, JdbcConnectionConfig.java	Introduces a new configuration option ("dialect") to support explicit dialect selection.
docs/*	Updates documentation to reflect the new dialect configuration option.

Comments suppressed due to low confidence (1)

seatunnel-connectors-v2/connector-jdbc/src/main/java/org/apache/seatunnel/connectors/seatunnel/jdbc/internal/dialect/JdbcDialectLoader.java:65

• Consider enhancing the check for 'dialect' to also verify that it is not an empty or blank string. For example: 'if (dialect != null && !dialect.trim().isEmpty()) {'.

if (dialect != null) {

[Copilot]

[nitpick] There is a missing space after the comma in 'For example,when using starrocks,'.

Suggested change

	| dialect | String | No | - | The appointed dialect, if it does not exist, is still obtained according to the url, and the priority is higher than the url. <br/> For example,when using starrocks, you need set it to `starrocks` |
	| dialect | String | No | - | The appointed dialect, if it does not exist, is still obtained according to the url, and the priority is higher than the url. <br/> For example, when using starrocks, you need set it to `starrocks` |