[dfmc-testing] Revert "remove more unneeded files"

This reverts commit dccd85c08a164ea38e8630b0f025b845d11ec322.
[dfmc-testing] Remove unused / duplicate files.
[dfmc-testing] Switch from functional-dylan to common-dylan.
[dfmc-testing] Clean up whitespace.
[dfmc-testing] Remove unused manual-compiler-test macro.
[dfmc-testing] Don't use dfmc-execution.
[dfmc-testing] Make compiler back-ends available.
[dfmc-testing] Improve formatting.
[projects] Set platform name correctly on string-template projects.
[dfmc-testing] Minor renamings.
[dfmc-testing] Bring in testworks, but don't convert to it yet.
[dfmc-testing] Don't export anything.
[dfmc-testing] Switch typist-algebra tests to testworks.
Merge pull request #777 from waywardmonkeys/bring-back-dfmc-testing

Bring back dfmc testing