unify and reduce contextual requirements

[cvogt]

a lot of methods / classes take a bunch of contextual arguments, most as implicits. Logger, transientCache, classLoaderCache, cbtLastModified, mavenCache, etc.

We should reduce the number of absolute arguments and whatever remains entirely implicit. Reducing can happen by either grouping things that always appear together, or by pulling the things that need them (e.g. BoundMavenDependency) deep inside outside of these functions instead and taking them as arguments instead, effectively moving the context dependencies further outside.

This standardization aims:

• reduce the number of very frequent context arguments for more concise code
• make all that remain implicit for more concise code
• reduce the required ones for easier use of the functionality as libraries outside of CBT
• reduce (or ideally remove) the coupling of a lot of functionality with CBT internal contexts