feat: Add IBM Cloud Logs Extensions API support

[Suruthi-G-K]

Description

This PR adds Terraform support for IBM Cloud Logs Extensions API, enabling users to manage extension deployments.

Changes

New Resources

• ibm_logs_extension_deployment - Manage extension deployments

New Data Sources

• ibm_logs_extension - Read single extension details
• ibm_logs_extensions - List all available extensions
• ibm_logs_extension_deployment - Read extension deployment details

Implementation Details

• Extension deployments are identified by extension ID (string like "IBMCloudant")
• Resource ID format: region/instance_id/extension_id
• Tests dynamically fetch extension metadata for valid test data
• Error handling follows existing resource patterns using flex.TerraformErrorf

Testing

• ✅ All unit tests passing
• ✅ Acceptance tests passing
• ✅ Build successful with no compilation errors

Checklist

• Provider registration complete
• Resource schema with all required fields
• CRUD operations implemented
• Error handling matches existing patterns
• Tests added and passing
• Documentation comments added

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Relates OR Closes #0000

Output from acceptance testing:

$ make testacc TEST=./ibm/service/logs TESTARGS='-run=TestAccIbmLogsExtension'
=== RUN   TestAccIbmLogsExtensionDeploymentDataSourceBasic
--- PASS: TestAccIbmLogsExtensionDeploymentDataSourceBasic (21.85s)
=== RUN   TestAccIbmLogsExtensionDataSourceBasic
--- PASS: TestAccIbmLogsExtensionDataSourceBasic (13.34s)
=== RUN   TestAccIbmLogsExtensionsDataSourceBasic
--- PASS: TestAccIbmLogsExtensionsDataSourceBasic (13.70s)
=== RUN   TestAccIbmLogsExtensionDeploymentBasic
--- PASS: TestAccIbmLogsExtensionDeploymentBasic (22.04s)
PASS
ok  	github.com/IBM-Cloud/terraform-provider-ibm/ibm/service/logs	72.765s
...