feat(ingest): lookml - support for git checkout

[shirshanka]

Checklist

• The PR conforms to DataHub's Contributing Guideline (particularly Commit Message Format)
• Links to related issues (if applicable)
• Tests for the changes have been added/updated (if applicable)
• Docs related to the changes have been added/updated (if applicable). If a new feature has been added a Usage Guide has been added for the same.
• For any breaking change/potential downtime/deprecation/big changes an entry has been made in Updating DataHub

[github-actions]

Unit Test Results (metadata ingestion)

       8 files  ±0         8 suites  ±0   56m 3s ⏱️ +24s
   709 tests +1     706 ✔️ +1  3 💤 ±0  0 ❌ ±0 
1 418 runs  +2  1 412 ✔️ +2  6 💤 ±0  0 ❌ ±0 

Results for commit 73926fb. ± Comparison against base commit d1cfdf1.

♻️ This comment has been updated with latest results.

[github-actions]

Unit Test Results (build & test)

521 tests   - 50   515 ✔️  - 56   14m 7s ⏱️ -21s
122 suites  - 19       0 💤 ±  0 
122 files    - 19       6 ❌ +  6 

For more details on these failures, see this check.

Results for commit 73926fb. ± Comparison against base commit d1cfdf1.

This pull request removes 50 tests.

datahub.protobuf.ProtobufDatasetTest ‑ customFieldVisitors
datahub.protobuf.ProtobufDatasetTest ‑ duplicateNested
datahub.protobuf.ProtobufDatasetTest ‑ googleTimestamp
datahub.protobuf.ProtobufDatasetTest ‑ messageA
datahub.protobuf.ProtobufDatasetTest ‑ messageB
datahub.protobuf.ProtobufDatasetTest ‑ messageC
datahub.protobuf.ProtobufDatasetTest ‑ messageC2NestedOneOf
datahub.protobuf.ProtobufDatasetTest ‑ noSchemaTest
datahub.protobuf.ProtobufDatasetTest ‑ platformSchemaTest
datahub.protobuf.ProtobufUtilsTest ‑ registryTest
…

♻️ This comment has been updated with latest results.