Add branches for 3.0.x and 4.x

[wyldckat]

This was asked by SKS13 via PM and then posted here: https://www.cfd-online.com/Forums/openfoam-programming-development/185390-evapvofhardt-code-compilation-error.html

As a reminder, the main thread on this topic was: https://www.cfd-online.com/Forums/openfoam-programming-development/135891-problem-compiling-custom-solver-evapvofhardt.html#post642578