[flang][driver] Add support for `-J/-module-dir`

[flang][driver] Add support for `-J/-module-dir`

Add support for option -J/-module-dir in the new Flang driver.  This
will allow for including module files in other directories, as the
default search path is currently the working folder. This also provides
an option of storing the output module in the specified folder.

Differential Revision: https://reviews.llvm.org/D95448