Add CI stage that looks for simple code issues in Fortran (currently: missing implicit none)

What has been done:

• Added stage in pipeline that uses a script (https://github.com/eirik-kjonstad/fortran-code-quality) to looks for various "code quality" problems.
• It currently prints information regarding: subroutine length, missing argument intents, number of arguments, and missing implicit none. However, only when "implicit none" is missing does the pipeline fail.

Should there be updates to the changelog?

• Yes

Should the patch number in parameters.F90 be updated?

• No

Should there be updates to the website?

• No

Is the code compliant with the style guide?

• Do's and dont's yes
• Documentation style yes