EZP-30754: Fixed handling always available flag for ContentInfo update

[alongosz]

Question	Answer
JIRA issue	EZP-30754
Bug/Improvement	yes
New feature	no
Target version	6.13, 7.5, master (8.0@dev)
BC breaks	no
Tests pass	TBD
Doc needed	no

This PR fixes two separate issues, related to handling of the always available flag, which occur during ContentInfo (Content metadata) update.

The first issue is about updating only the always available flag and nothing else, as reported via kaliop-uk/ezmigrationbundle#209 and EZP-30754.
To solve that we need to check if there's anything to update before trying to execute database update.
It's not easy with our own database abstraction layer, therefore this PR refactors \eZ\Publish\Core\Persistence\Legacy\Content\Gateway\DoctrineDatabase::updateContent to rely on \Doctrine\DBAL QueryBuilder for that.

The second issue is about fixing erroneous type casting when setting always available flag, both in Legacy Storage Persistence Content Mapper and in the Content\Gateway\DoctrineDatabase::updateAlwaysAvailableFlag method. The latter mistake caused ContentInfo::alwaysAvailable being always set to true during main Translation update, regardless of the actual state.

Implemented also integration tests covering both updating main translation and always available flag only. Those are the special cases handled by different path of code.

QA

The second issue is reproducible only on the API level unfortunately. Content Info after updating main language code (via ContentMetadataUpdateStruct) has always available flag always set to true.
To see the bug you could use app:test command available on my 1.13-based branch: https://github.com/alongosz/ezplatform/tree/ezp-30754-cmd-for-qa
(observe that alwaysAvailable changes though updateStruct didn't touch it).

TODO:

• Merge up: add is_hidden column (777d30f#diff-92b3a16009ff423f5d87182e80ea7dcaR304).
• Refactor Content GW (\eZ\Publish\Core\Persistence\Legacy\Content\Gateway\DoctrineDatabase) updateContent method to rely on \Doctrine\DBAL Query Builder.
• Add checking if there's anything to update before executing update query in the updateContent method.
• Fix setting always available flag in the Persistence mapper and updateAlwaysAvailableFlag.
• Implement tests.
• See if CI passes.
• Fix new code according to Coding Standards ($ composer fix-cs).
• Ask for Code Review.

[adamwojs]

@alongosz CI failure is caused by code style issues. Is it related to #2857?

[alongosz]

@alongosz CI failure is caused by code style issues. Is it related to #2857?

Yes.

[micszo]

Retested first and second issue on eZ Platform EE v1.13.5 with this branch.
Used the draft PR to test on 2.5.