Metronome marks with more options

If you need, in metronome marks:

This snippet also changes the size of metronome marks: IMPORTANT:

This snippet is based on a snippet by Arnold Theresius. The original snippet create a formatter called format-metronome-markup-approx, and the default value to tempoEquationText in that snippet is "≈". I changed back this default to Lilypond default, and added the tempoBetweenText property. Also, I changed the sizing of some elements, as described above.

Original snippet by Arnold Theresius