In chgres_cube, increase character length of string array containing grid file names

[gsketefian]

DESCRIPTION:

In chgres_cube, in file model_grid.F90, the array containing the names of the grid tile files is declared as follows:

character(len=25)                 :: grid_files(num_tiles)

In the SRW App (ufs-srweather-app), the name of the grid file can exceed 25 characters when the grid gets very fine (e.g. 1km or less) and the C-resolution goes into 5 digits, e.g. a file name of C10010_grid.tile7.halo4.nc, which is 26 characters.

SOLUTION:

Change the declaration of the grid_files array to have a longer string length, e.g. 50 characters:

character(len=50)                 :: grid_files(num_tiles)

I have tested this and it works for the specific case described above.

[GeorgeGayno-NOAA]

Branch at 91049dc was tested on Jet. All chgres regression tests passed. Will issue PR.