refactor(upgrade): move restore-indices boot steps to system-update job

[Dutt23]

## Why

Three index-restore steps (`RestoreColumnLineageIndices`, `RestoreFormInfoIndicesStep`, `RestoreGlossaryIndices`) were running inside GMS bootstrap — blocking startup and running sequentially before GMS could serve traffic. These steps are non-critical to request serving and shouldn't hold up the main startup path.

## What

Moves all three restore-indices steps from `BootstrapManagerFactory` (blocking, sequential) to the `datahub-upgrade` system-update job (non-blocking, out-of-band).

### Changes

- Added wrapper + step classes under `system/restoreindices/{columnlineage,forminfo,glossary}`, preserving all original migration logic
- Wired 3 new beans in `NonBlockingConfigs` with enabled flags
- Added config properties (all default `true`):

  systemUpdate.restoreColumnLineageIndices.enabled
  systemUpdate.restoreFormInfoIndices.enabled
  systemUpdate.restoreGlossaryIndices.enabled

- Removed steps from `BootstrapManagerFactory`; dropped now-unused `_entityRegistry` field and `EntityRegistryFactory` import
- Deleted original boot step source files and their tests
- Added functional tests covering empty-data, MCL-emission, and failure paths

## Impact

GMS startup no longer does work on index restoration. Reduces startup time and eliminates a potential source of slow/failed deployments when index data is large.

> **Note:** To disable any step individually, set the corresponding `systemUpdate.restore*.enabled` flag to `false` in your config.

[codecov]

Codecov Report

❌ Patch coverage is 85.92058% with 39 lines in your changes missing coverage. Please review.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
...reindices/forminfo/RestoreFormInfoIndicesStep.java	81.25%	14 Missing and 7 partials ⚠️
...reindices/glossary/RestoreGlossaryIndicesStep.java	90.00%	4 Missing and 3 partials ⚠️
...columnlineage/RestoreColumnLineageIndicesStep.java	92.30%	3 Missing and 2 partials ⚠️
...ces/columnlineage/RestoreColumnLineageIndices.java	77.77%	1 Missing and 1 partial ⚠️
...estoreindices/forminfo/RestoreFormInfoIndices.java	77.77%	1 Missing and 1 partial ⚠️
...estoreindices/glossary/RestoreGlossaryIndices.java	77.77%	1 Missing and 1 partial ⚠️

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[alwaysmeticulous]

🔴 Meticulous spotted visual differences in 2 of 1427 screens tested: view and approve differences detected.

Meticulous evaluated ~10 hours of user flows against your PR.

_{Last updated for commit 9a373ff merge. This comment will update as new commits are pushed.}

[codecov]

Bundle Report

Changes will increase total bundle size by 191 bytes (0.0%) ⬆️. This is within the configured threshold ✅

Detailed changes

Bundle name	Size	Change
datahub-react-web-esm	23.54MB	191 bytes (0.0%) ⬆️

Affected Assets, Files, and Routes:

view changes for bundle: datahub-react-web-esm

Assets Changed:

Asset Name	Size Change	Total Size	Change (%)
assets/index-*.js	79 bytes	8.86MB	0.0%
assets/en-*.js	72 bytes	225.17kB	0.03%
assets/de-*.js	40 bytes	47.72kB	0.08%