Changes

Removing l_interp_prescribed_params from setup_clubb_pdf_params.
The flag has been removed and so has any code underneat a logic statement
involving this statement unless it has multiple flags. The else statement
in the if block involving this flag has been set to execute without an
if block.
For ticket #916
Results are BFB identical. Additionally, complex logic statements
with the use of more flags had those flags adjusted and BFB results
were also confirmed with these changes.

Changes readiopdata_module to use nf90 subroutines

Switches nf_real to nf90_real

Replaces nf_get_var_<type> family with nf90_get_var

Moves more calls to nf90

Replace nf_inq_dimlen with nf90_inquire_dimension

Fix spelling of nf90_inquire_variable on use statement

Replace nf_inq_dimname with nf90_inquire_dimension

Replace nf_get_vara_ subroutines with nf90_get_var

Remove `include netcdf.inc` statements

Remove redundant code

Use nf90_inquire_dimension to manually set count value for nf90_get_var

Issue larson-group/clubb#900

Add workaround for k=1

Switch to using nf90_inquire_variable to find information to allocate var

Fix manual specification of values

Fix issues with deallocation of variables

Remove the allocatable attribute from var in get_netcdf_var1d_real
Add deallocate statement for local allocatables in get_netcdf_var1d_real

Rewrite some of get_netcdf_var2d_real

 - nf90_get_var is now only called once
 - Due to problems with the order of the values, a new section has been added
   to the subroutine

Add deallocate statement to get_netcdf_var2d_real after change

Remove unused variable 'length' in get_netcdf_var*d_real

Add additional comments

Add statement to ensure dplevs initializes with zeroed values

Revert "Add workaround for k=1"

This reverts commit 79a8797cbba6545390c196dd3a14337b351da1b8.

The workaround that was added is no longer necessary.

Update comments and variable names as requested

Fix comments

Set intent of var back to inout, as in the case of dplevs, it may not assign all values

Remove some of the old variables from get_netcdf_var2d_real