EPA: some cleanups after the merge, as per #19579

Remove EpaAnn type synonym, rename EpaAnn' to EpaAnn. Closes #19705 (closed)

Updates haddock submodule

--

Change

  data EpaAnchor = AR RealSrcSpan
                 | AD DeltaPos

To instead be

  data EpaAnchor = AnchorReal RealSrcSpan
                 | AnchorDelta DeltaPos

Closes #19699 (closed)

--

Change

  data DeltaPos =
    DP
      { deltaLine   :: !Int,
        deltaColumn :: !Int
      }

To instead be

  data DeltaPos
    = SameLine { deltaColumn :: !Int }
    | DifferentLine { deltaLine :: !Int, startColumn :: !Int }

Closes #19698 (closed)