ScalafmtReflectConfig: add access to indents

[kitbellew]

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[kitbellew]

@unkarjedy should we consider adding to the main codebase the logic you added to intellij, and simply switch to using it?

[unkarjedy]

@kitbellew
Yeah, my initial commit in IntelliJ was named

2/11/2019 12:19 temporary copied sources of scalafmt-dynamic #SCL-14957
JetBrains/intellij-scala@03adc3e

🤦‍♂️

It just ("simply" 😃) requires some effort.
We need to:

1. find/review all patches in IntelliJ copy of scalafmt.dynamic
   (they were required to properly work with IntelliJ and it was much easier to patch it within IntelliJ repo)
2. extract required abstractions to traits in order the patched version doesn't rely on IntelliJ implementation classes
   Example of such abstraction: artifact downloader
3. pass those abstractions via some parameters
4. move this to scalameta/scalafmt repo and ensure it works well

I never got to this because it worked fine and we always have something major to do 😑