Fix AeroDyn WriteOutput linearization (and cleanup some code)

[bjonkman]

This PR can be merged after #1042.

Feature or improvement description This pull request primarily cleans up some of the AeroDyn code (and its submodules) to better sync with the Envision AeroDyn code base. It also addresses an issue where the WriteOutput values in AeroDyn were not updated in linearization (after multi-rotor capability was added).

• AeroAcoustics

  • removed unused variables
  • made exponents integer numbers instead of reals where appropriate (to make the math faster/more accurate)
  • updated subroutine arguments to pass arrays of AFI(:) instead of AFI(:)%BL_File. At least some versions of the gcc compiler do not handle the arrays properly the way they were previously written.
  • substituted numeric value of 2 with equivalent parameter X_BLMethod_Tables where appropriate
  • converted print * statements with calls to WrScr()

• AeroDyn

  • updated computation of WriteOutput arrays so it can appear in linearization (see https://github.com/OpenFAST/openfast/issues/972)
  • removed unused variables
  • added rTipFix to sync better with Envision code base (will update its usage later)
  • updated formatting of nodal output channel names in AD summary file

• VS Build

  • AeroDyn driver solution now warns for unused variables in Debug configuration.

Related issue, if one exists #972

Impacted areas of the software AeroDyn, linearization with AeroDyn WriteOutputs

Test results, if applicable I would expect this to get the same test results as #1042.