refactor(looker): Migrating to new browse path format

[jjoyce0510]

Summary

In this PR, we migrate the browse paths produced by looker sources to the new format, which does NOT mandate that the path ends with the asset's name or id. Learn more about the migration here: https://github.com/datahub-project/datahub/blob/648d10c16e2591e43b96f930997fa5490e27aa06/docs/advanced/browse-paths-upgrade.md

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   58m 19s ⏱️ - 4m 33s
   708 tests ±0     705 ✔️ +1  3 💤 ±0  0 ❌  - 1 
1 418 runs  ±0  1 412 ✔️ +1  6 💤 ±0  0 ❌  - 1 

Results for commit ce15450. ± Comparison against base commit 98ee621.

♻️ This comment has been updated with latest results.

[github-actions]

Unit Test Results (build & test)

521 tests  ±0   521 ✔️ ±0   14m 48s ⏱️ -18s
121 suites ±0       0 💤 ±0 
121 files   ±0       0 ❌ ±0 

Results for commit ce15450. ± Comparison against base commit 98ee621.

♻️ This comment has been updated with latest results.