[8.0.x] Code formatting

[NeQuissimus]

We have different styles floating around the code right now.
Let's use Scalafmt to make things consistent.

@fommil says a new sbt plugin is going to be available in the near future, so we can probably wait for that.

This pretty much sums up step 2:

then we can fight over settings, I have some pretty aggressive settings

This is @fommil's set of preferences:

align = most
continuationIndent.defnSite = 2
assumeStandardLibraryStripMargin = true
docstrings = JavaDoc
lineEndings = preserve
includeCurlyBraceInSelectChains = false
danglingParentheses = true
spaces {
  inImportCurlyBraces = true
  inByNameTypes = false
}
optIn.annotationNewlines = true

rewrite.rules = [SortImports, RedundantBraces]

This is what I currently use:

maxColumn = 120
align.openParenCallSite = false
align.openParenDefnSite = false
align.ifWhileOpenParen = false
continuationIndent.defnSite = 2
continuationIndent.extendSite = 2
optIn.selfAnnotationNewline = false
optIn.configStyleArguments = false
spaces.afterTripleEquals = true
spaces.inImportCurlyBraces = true
danglingParentheses = true
includeCurlyBraceInSelectChains = false
importSelectors = singleLine

Related to #1464

[fommil]

also, in the meantime, we could use the hack I use, which is about x10 faster than the scalafmt plugins that are out there

// WORKAROUND: until https://github.com/scalameta/scalafmt/issues/1081
commands += Command.args("fmt", "scalafmt CLI") {
  case (state, args) =>
    val Right(scalafmt) =
      org.scalafmt.bootstrap.ScalafmtBootstrap.fromVersion("1.3.0-16-49815ab4")
    scalafmt.main(
      List(
        "--config",
        "project/scalafmt.conf",
        "--git",
        "true",
        "--exclude",
        "testing",
        "--non-interactive"
      ) ++: args
    )
    state
}

plus copy https://github.com/ensime/ensime-server/blob/3.0/project/Bootstrap.scala into project/