Remove redundant locators and clean-up leftover pre-modules code

[Su5eD]

Cleans up leftover code from before the module era that is no longer functional in modern modlauncher versions which make use of modules.

The reason for skipping a deprecation phase is that said code is no longer used by modlauncher itself and does nothing on its own, whereas deprecated code would still be considered functional. There is no reason for us to keep this code. It's outdated and should be removed immediately to avoid confusing users.

Additional class/resource locators

Removes 2 unused locator methods in ITransformationService:

• additionalClassesLocator
• additionalResourcesLocator

These methods have not had any effect since modlauncher 9+. With the module system in place, all classes and resources must be associated with a source module, and thus anonymous providers are no longer viable. Instead, modders are encouraged to use the scan callback methods (beginScanning, completeScan) to load additional jars at runtime.

TransformingClassLoaderBuilder

The TransformingClassLoaderBuilder class was previously used to create a customized classloader instance with extra transformable paths or a class byte provider function. Both of these are no longer used by modlauncher, as the module layers are immutable and cannot be expanded. The transforming class loader pulls all of its data from the GAME module layer.

Fixes #89
Fixes #111

[Technici4n]

I think this is a great initiative. We can always bump the major version if we are afraid of this breaking change.

[Technici4n]

This is good and will indeed not break anything.