Null checking the associated buff belonging to a DOT

[Nebby1999]

Fixes issue number #324, Simply checks if the BuffDef associated to the DOT exists, if not, continues adding it to the dot catalog as normal.

Debug.LogInfo message properly displays this change, with a new message that simply says "Custom Dot (Index: {dotDefIndex}) with no associated Buff added".

Also applied the same changes to the unrolled version, associatedBuff is now null by default and its not mandatory-

[harbingerofme]

What the hell is this

Forgive my language, a bit tired.

The ternary statement that is very long doesn't make sense to use when all you are doing with it is immediately logging it and then discarding it.

I would love to either see a full blown if, or moving the ternary statement to use less than an entire line.

R2Api.Logger.logInfo($"Custom Dot (Index: {dotDefIndex} " + dotDef.associatedBuff == null ? "added." : $"that uses Buff : {dotDef.associatedBuff.name} added");