+Make units argument mandatory for get_param_real

  This commit includes changes to the get_param_real and log_param_real
interfaces to make the units arguments mandatory.  It also adds an optional
unscale argument to the log_param_real interfaces.  Without other changes in the
previous commits, it will cause the MOM6 code to fail to compile.  However, by
itself this commit does not change any answers or output.

src/framework/MOM_file_parser.F90

@@ -1419,7 +1419,7 @@ subroutine log_param_real(CS, modulename, varname, value, desc, units, &
   real,                       intent(in) :: value   !< The value of the parameter to log
   character(len=*), optional, intent(in) :: desc    !< A description of this variable; if not
                                          !! present, this parameter is not written to a doc file
-  character(len=*), optional, intent(in) :: units   !< The units of this parameter
+  character(len=*),           intent(in) :: units   !< The units of this parameter
   real,             optional, intent(in) :: default !< The default value of the parameter
   logical,          optional, intent(in) :: debuggingParam !< If present and true, this parameter is
                                          !! logged in the debugging parameter file
@@ -1457,7 +1457,7 @@ subroutine log_param_real_array(CS, modulename, varname, value, desc, &
   real, dimension(:),         intent(in) :: value   !< The value of the parameter to log
   character(len=*), optional, intent(in) :: desc    !< A description of this variable; if not
                                              !! present, this parameter is not written to a doc file
-  character(len=*), optional, intent(in) :: units   !< The units of this parameter
+  character(len=*),           intent(in) :: units   !< The units of this parameter
   real,             optional, intent(in) :: default !< The default value of the parameter
   logical,          optional, intent(in) :: debuggingParam !< If present and true, this parameter is
                                          !! logged in the debugging parameter file
@@ -1782,7 +1782,7 @@ subroutine get_param_real(CS, modulename, varname, value, desc, units, &
                                          !! read from the parameter file and logged
   character(len=*), optional, intent(in)    :: desc    !< A description of this variable; if not
                                          !! present, this parameter is not written to a doc file
-  character(len=*), optional, intent(in)    :: units   !< The units of this parameter
+  character(len=*),           intent(in)    :: units   !< The units of this parameter
   real,             optional, intent(in)    :: default !< The default value of the parameter
   logical,          optional, intent(in)    :: fail_if_missing !< If present and true, a fatal error occurs
                                          !! if this variable is not found in the parameter file
@@ -1830,7 +1830,7 @@ subroutine get_param_real_array(CS, modulename, varname, value, desc, units, &
                                          !! read from the parameter file and logged
   character(len=*), optional, intent(in)    :: desc    !< A description of this variable; if not
                                          !! present, this parameter is not written to a doc file
-  character(len=*), optional, intent(in)    :: units   !< The units of this parameter
+  character(len=*),           intent(in)    :: units   !< The units of this parameter
   real,             optional, intent(in)    :: default !< The default value of the parameter
   logical,          optional, intent(in)    :: fail_if_missing !< If present and true, a fatal error occurs
                                          !! if this variable is not found in the parameter file