Implemeting Finnish ASCIIMath #859

The situation now is that Finnish ASCIIMath isn't implemented in MathCAT, since I asked it to be taken out. The reason before was that it didn't have updated rules based on the tests I had made and the I couldn't run the tests, because of some Rust-related reason (if I remember right). Some of this discussion was in #276

My questions now are that are the Finnish ASCIIMath rules updated? Do they reflect the tests I had made before?

My idea was to make more tests in about two weeks if it is needed.