feat: provide override for eager loading models on different connections

[wojo1206]

• Added or updated tests
• Documented user facing changes
• Updated CHANGELOG.md

Changes

Introduced config var that can override isSameConnection() for batchload relations. This fixes n+1 problem for models that exists on different connections.

Breaking changes

None

[spawnia]

Have you actually tried this? The check to avoid batch loading if separate connections are involved was added because the resulting database queries for batch loading uses tables of both models, which would not work when they are on different databases. In what instance would this not hold true?

[spawnia]

Please revert reformatting.

[wojo1206]

Yes, I use this fork on my production already. Works like a charm. I think you are suggesting that the check to avoid batch loading on separate connections creates possible conflicts due to resulting queries not being database prefixed? I don't know what is the default Eloquant behavior nowadays. It is good practice to include databases prefixes in queries. I believe in the past the Eloquant didn't do that. I have multi database setup and I override getTable() on all models to ensure that my queries are database prefixed.

I think, this config var is valuable addition to the project because it isn't braking change and provides option to the users. In future, this functionality should better align to what the recent Eloquant behavior is.