Support 0.8.6 IR jars without breaking backwards compatibility

[seraxis]

When version 0.8.6 was released it was not mentioned anywhere that this would break compatibility with IR jars from previous versions, resulting in a crash with no feedback as to what went wrong. This adds backwards compatibility for pre-0.8.6 IR jars as nothing has actually changed between the two versions except the method signatures and the inclusion of a wrapper object IR login can try the 0.8.6 login method before softly falling back to the pre-0.8.6 case in MainController without needing to break any existing behaviour.

[SackMagiclight]

Basically, only the latest beatoraja version should be supported; other choices are left to the IR side. In other words, the IR side should be responsible for the implementation associated with it. (I do the same).

This is not a change that should be put into the beatoraja itself.

(deepl)

[seraxis]

I see, thank you for responding, I'd like @exch-bms2 to close this if that's the final decision on the matter