OMP directives not captured as UPPERCASE keywords by lfric_styling #255

While reviewing changes for MetOffice/casim#19, some imported OMP directives had been only partially or not at all, converted from the UM UPPERCASE to the LFRic lowercase convention.

Some keywords in OMP directives in imported UM modules are not being converted from UPPERCASE to lowercase by the lfric_styling scripts.

Keywords to be added:
STATIC, DYNAMIC, PARALLEL SCHEDULE NO WAIT DEFAULT, SHARED,