Generalize field declaration for the least squares reconstruction routines

What is the new feature

The field declaration of the LSQ reconstruction routines has been generalized slightly, in order to make the routines applicable to the ocean surface wave model ICON-wave.

How is it implemented

Currently, the 'vertical' or '3rd' dimension of the local field z_b is implicitly identified with p_patch%nlev. This is fine for the atmosphere model, but does not work for ICON-WAVE, where the 3rd dimension is the total number of spectral wave energy bins. This issue has been solved by replacing

REAL(wp) :: z_d(3, nproma, nlev)

with

REAL(wp) :: z_d(3, nproma, elev)

As a side effect, nlev is no longer needed by the reconstruction routines. The argument lists have been adapted accordingly.

@m222072

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