[BUG] Datasource testing connection don't validate endpoints with path

[xinruiba]

Task List

• [BUG] Cluster endpoint test connection passed unexpectly #5707
• [BUG] Cluster endpoint URL pattern validation for Server and Serverless domain in UX component before sending test connection request (Optional) #5706

Describe the bug

If cx adds endpoint with path appended (for example: https://OpenSearchEndpoint/_dashboards) as a datasource, connection test will pass, but cx can't create index pattern or add sample data;

We may need to validate endpoint's path is empty when testing connection

To Reproduce
Steps to reproduce the behavior:

1. Go to "Dashboards Management" ---> "Data Sources"
2. Click on "Create data source connection"
3. Fill in the form with DataSource Title. eg: "test"
4. Fill in the form with DataSource Endpoint followed with a path name. eg: "https://OpenSearchEndPoint/_dashboard"
5. Click on "Test Connection" the test will pass
6. Go to "Home" ---> "Add Sample Data" ---> "Data Source" choose Test --->
7. Error shows up: sample data not able to be added

Expected behavior
DataSource should not be able to created with an endpoint appended with a path.
We should do URL validation to make sure not path name appended to a datasource endpoint.

OpenSearch Version
2.11

Dashboards Version
2.11

Plugins

Please list all plugins currently enabled.
N/A

Screenshots

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Host/Environment (please complete the following information):

• OS: Linux
• Browser and version: Chrome Version 120.0.6099.129

Additional context

Add any other context about the problem here.

[xinruiba]

I have a proposal to fix this issue. Creating a PR now.