[Internal] Migrate Share Data Source to Plugin Framework

[rauchy]

Changes

This PR migrates the share/shares data sources to the Plugin framework. The code was largely copied "as is" from the previous implementation of the share data source, with the necessary adaptations made for integration with the Plugin framework.

Tests

Note: current tests create shares using the SDKv2 resource, but fetch them using the new plugin framework data source. Once the resource migration will be merged, I will amend this. Edit: Now that the resource itself is merged, the acceptance tests use the plugin framework's version of the resource.

• [x] make test run locally
• [ ] relevant change in docs/ folder
• [x] covered with integration tests in internal/acceptance
• [x] relevant acceptance tests are passing
• [x] using Go SDK

[alexott]

@rauchy I think that it makes sense just to duplicate tests, not to replace resources/data sources, so we keep tests for SDK-based resources as well, and remove the duplicate tests when we replace SDK-based with plugin framework-based

[rauchy]

@alexott that was exactly what I was about to propose :)

[eng-dev-ecosystem-bot]

Test Details: go/deco-tests/11591746843