bounc needs to work with spec files with different dimensions

[aliabdolali]

Is your feature request related to a problem? Please describe.
ww3_bounc requires consistent dimension and it gives an error in case there are multiple spec.nc files as boundary conditions and each has different dimensions (NKI,NTHI,MTI).

spec1.nc [36x35x145]
spec2.nc [36x35x141]

error:

 *** WAVEWATCH III ERROR IN W3BOUNC:
     INCONSISTENT SPECTRAL DIMENSION FOR FILE ./src/ww3_2D_N_p11_201108_spec.nc
     NKI = 35 DIFFERS FROM NK1 = 35
     OR NTHI = 36 DIFFERS FROM NTH1 = 36
     OR NTI =  145 DIFFERS FROM NT1 =  141

Describe the solution you'd like
Multiple spec.nc with different dimension should be read by bounc