Adds allocate_diag_field_output_buffers() to fms_diag_object_mod

[ganganoaa]

Description
Update relates to a new addition of member routine, allocate_diag_field_output_buffer(), to the type fmsDiagObject_type in the fms_diag_object_mod. The routine fms_diag_output_buffer_create_container() in the module, fms_diag_output_buffer_mod, is declared public for visibility issue. The dependency of module, fms_diag_output_buffer_mod, is inserted in /diag_manager/Makefile.am. The use statement for the fms_diag_yaml_mod is also updated to include the DiagYamlFilesVar_type. get_var_type() and get_default_missing_value() are added to use diag_data_mod and use fms_diag_field_object_mod respectively. The platform_mod is included in the fms_diag_object_mod to access the precision related variables (r4_kind, r8_kind, etc.).

Fixes # (issue)

How Has This Been Tested?
Ci

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules
• New check tests, if applicable, are included
• make distcheck passes