Fix dav properties column types

[tcitworld]

Summary

• First commit changes column propertyvalue from TEXT type to BLOB as it may contain null 0x00 characters because of php serialization #37754
  • after removing all serialized data (that have very good chances to be invalid)
  • by creating a new temporary column
  • moving data to it
  • dropping the old column
  • adding a new column with the right type
  • moving data to it
  • resetting not null on the new column
  • dropping the temporary column
• Second one increases simply propertypath column length #9907

If changing the type of the column can't be done, we'll need to create a new column and move data

TODO

• [x] SQLite is accepting pretty much anything ✅
• [x] MySQL/MariaDB ✅ just needs the index to be on a prefix
• [x] Test on PostgreSQL ❌ (needs some cast magic)
• [x] Test on Oracle ❌ (is being Oracle)

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• [ ] Tests (unit, integration, api and/or acceptance) are included
• [ ] Screenshots before/after for front-end changes
• [ ] Documentation (manuals or wiki) has been updated or is not required
• [ ] Backports requested where applicable (ex: critical bugfixes)

[tcitworld]

@skjnldsv This one is important and I need some help on the database migration.

[rakekniven]

Any chance this PR get's some love?

[tcitworld]

For PostgreSQL : https://stackoverflow.com/questions/19300113/unable-to-convert-postgresql-text-column-to-bytea For Oracle : https://asktom.oracle.com/ords/f?p=100:11:::::P11_QUESTION_ID:510622111991

If we have less than 50k rows (value yet to determine), perform the migrations straight away. Otherwise, skip the migration, set an appconfig and add a red flag in system check. Then include as an expensive repair step.

[tcitworld]

Fixed through https://github.com/nextcloud/server/pull/49528