T15785 change exists to has

[niden]

Hello!

• Type: enhancement
• Link to issue: [NFR]: Change exists to has #15785

In raising this pull request, I confirm the following:

• I have read and understood the Contributing Guidelines
• I have checked that another pull request for this purpose does not exist
• I wrote some tests for this PR
• I have updated the relevant CHANGELOG
• I have created a PR for the documentation about this change

Marked as deprecated:

• Phalcon\Mvc\Model::existsBelongsTo()
• Phalcon\Mvc\Model::existsHasMany()
• Phalcon\Mvc\Model::existsHasOne()
• Phalcon\Mvc\Model::existsHasOneThrough()
• Phalcon\Mvc\Model::existsHasManyToMany()
• Phalcon\Translate\Adapter\Csv::exists()
• Phalcon\Translate\Adapter\Gettext::exists()
• Phalcon\Translate\Adapter\NativeArray::exists()

Added:
- Phalcon\Mvc\Model::hasBelongsTo()
- Phalcon\Mvc\Model::hasHasMany()
- Phalcon\Mvc\Model::hasHasOne()
- Phalcon\Mvc\Model::hasHasOneThrough()
- Phalcon\Mvc\Model::hasHasManyToMany()
- Phalcon\Translate\Adapter\Csv::has()
- Phalcon\Translate\Adapter\Gettext::has()
- Phalcon\Translate\Adapter\NativeArray::has()

Thanks