Add POSTPROCESSING_TOOL_NAME to config_component.xml

[ekluzek]

In order to provide the name of the postprocessing tool that's being used for a case we want to add POSTPROCSSING_TOOL_NAME

Add something like the following to: cime_config/config_component.xml

  <entry id="POSTPROCESSING_TOOL_NAME">
    <type>char</type>
    <default_value>CUPiD</default_value>
    <group>case_comp</group>
    <file>env_case.xml</file>
    <desc>Name of the postprocessing tool (for documentation only - DO NOT EDIT)</desc>
  </entry>

This is in the case_comp group as that has the names of the components and here the name for the coupler/driver.

We talked about doing this in CUPiD and then @JEdwards suggested that the definition should be here.

See this comment here:

NCAR/CUPiD#399 (comment)