## Goal
We have identified that sync-metadata (which is called during new
workspace initialization) is slow mainly because of workspaceMigration
application (migration-runner module). This is due to the fact that we
use typeORM API to perform schema changes, which often query the
existing schema. As querying the existing schema is costly (especially
with ~1M existing columns) and as we already have what we need described
as metadata, we will use raw SQL directly. This should divide the
workspace initialization time by x2.
## How
This PR can be read in two commits:
1. Extract functions tied to column migrations in a separate service
(`workspace-migration-column.service`) + deprecate COMMENT column
migration type which is not useful since we are not using pg-graphql
anymore
2. Re-work `workspace-migration-column.service` to make it clearer + use
raw SQL
## Result
Before:
<img width="1367" alt="image"
src="https://github.com/user-attachments/assets/e730df7b-db7f-4433-9ce5-52841b010990"
/>
After:
<img width="1367" alt="image"
src="https://github.com/user-attachments/assets/72d2c2b1-2475-4541-a3d5-50b70824a2e4"
/>
## Manual Testing
- Sync-metadata OK
- Workspace init OK
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