Add `databricks_mlflow_experiment` data source

[840]

Changes

Add databricks_mlflow_experiment data source

Tests

Created 3 tests for this data source

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

Partially resolves #2301

[840]

Currently you can only fetch the mlflow_experiment data source using the name in this PR. I believe it would be nice to provide the option to fetch using the ID, as well. I have to read a bit more into this.

[codecov-commenter]

Codecov Report

Attention: 2 lines in your changes are missing coverage. Please review.

Comparison is base (4213468) 83.57% compared to head (9b8c8be) 83.57%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2389      +/-   ##
==========================================
- Coverage   83.57%   83.57%   -0.01%     
==========================================
  Files         168      169       +1     
  Lines       15083    15107      +24     
==========================================
+ Hits        12606    12625      +19     
- Misses       1736     1739       +3     
- Partials      741      743       +2     

Files	Coverage Δ
provider/provider.go	94.47% <100.00%> (+0.03%)	:arrow_up:
mlflow/data_mlflow_experiment.go	91.30% <91.30%> (ø)

... and 1 file with indirect coverage changes

[nkvuong]

@840 thank you for raising the PR. a couple of thoughts for the pending tasks

you could look at https://github.com/databricks/terraform-provider-databricks/blob/master/clusters/data_cluster.go for example of searching both by name & id

the Go SDK has GetExperiment method which takes an ExperimentId as well.

For acceptance tests, you could create an mlflow experiment and try to read it in the same block, similar to https://github.com/databricks/terraform-provider-databricks/blob/master/internal/acceptance/data_job_test.go

[840]

Blocked by databricks/databricks-sdk-go#428

[840]

Will continue this week or early next week.

[840]

@mgyucht WIP tag removed, should be ready!