Print - Add a local grid

[johnnyblasta]

Is your feature request related to a problem? Please describe.
Add a local grid of type letter and number (for rescue services use)

Describe the solution you'd like
In print settings it should be able to add a local grid on the map that is to be printed. Letters on one axis and numbers on the other axis. It should be optional on which axis the letters and numbers should be placed. Also it should be possible to define the size of the grid, for example 3x4 or 8x5. The color and thickness of the line in the grid should be possible to change, so that any problems with contrast against the background can be avoided.