Bugfix spheri3d + new example to test spherical coordinates in TELEMAC-3D

this fixes issue #971 (closed) the problem was that a routine was called twice in 3d, thus changing the coordinates twice, leading to weird numerical values. There was also an issue (pwithout influenc eon the results) for the case that the characteristic method was switch off.

A test case was added to show that this feature now works correctly. the test case is basically a 3d version of the existing m2wave tets case in telemac-2d. The tets was set up in such a way to stick as much as possible to the 2d case (so they do not necessary represent optimal settings). However a few changes were made: -user_fortran routines to adapt bathymetry and friction were not included. instead the mesh of the 2d case with those corrcetions was taken (because that was less work than adapting the userFortran) -wetting-drying was switch on, because of some issue with negative depths, which leads to negative layer thickness and crashes.

EDIT update before merge:

• 2 bug fixes were merged before in 2 different MR in !187 (merged) and !188 (merged),
• 1 change of default value was changed in #994 (closed)

This MR only contains a new example to test spherical coordinates in TELEMAC-3D, based on m2wave TELEMAC-2D example.