Add support for longer cross-memory server parms

[ifakhrutdinov]

Proposed changes

This PR extends the standard cross-memory server's service responsible for accessing configuration parameters and related data structures to allow it to handle PARMLIB parameter keys and values longer than 128 characters.

This PR addresses Issue: zowe/zss#684

Type of change

Please delete options that are not relevant.

• [x] Bug fix (non-breaking change which fixes an issue)

PR Checklist

Please delete options that are not relevant.

• [x] If the changes in this PR are meant for the next release / mainline, this PR targets the "staging" branch.
• [x My code follows the style guidelines of this project (see: Contributing guideline)
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] Relevant update to CHANGELOG.md
• [x] My changes generate no new warnings
• [x] I have added tests that prove my fix is effective or that my feature works, or describe a test method below

Testing

Regression testing

Existing short parameters should work as usual.

Support of long parameters testing:

To test long parameters, specify something like this in the ZIS PARMLIB member:

LONG_TEST_PARM=\
this_is_line_value_0123456789_0\
this_is_line_value_0123456789_1\
this_is_line_value_0123456789_2\
this_is_line_value_0123456789_3\
this_is_line_value_0123456789_4\
this_is_line_value_0123456789_5\
this_is_line_value_0123456789_6\
this_is_line_value_0123456789_7\
this_is_line_value_0123456789_8\
this_is_line_value_0123456789_9\
this_is_line_value_0123456789_10\
this_is_line_value_0123456789_11\
this_is_line_value_0123456789_12\
this_is_line_value_0123456789_13\
this_is_line_value_0123456789_14\
this_is_line_value_0123456789_15\
this_is_line_value_0123456789_16\
this_is_line_value_0123456789_17\
this_is_line_value_0123456789_18\
this_is_line_value_0123456789_19\
this_is_line_value_0123456789_20\
this_is_line_value_0123456789_21\
this_is_line_value_0123456789_22\
this_is_line_value_0123456789_23\
this_is_line_value_0123456789_24\
this_is_line_value_0123456789_25\
this_is_line_value_0123456789_26\
this_is_line_value_0123456789_27\
this_is_line_value_0123456789_28\
this_is_line_value_0123456789_29\
this_is_line_value_0123456789_30\
this_is_line_value_0123456789_31\
this_is_line_value_0123456789_32\
this_is_line_value_0123456789_33\
this_is_line_value_0123456789_34\
this_is_line_value_0123456789_35\
this_is_line_value_0123456789_36\
this_is_line_value_0123456789_37\
this_is_line_value_0123456789_38\
this_is_line_value_0123456789_39\
end

Without the fix, ZIS should terminate with an error on start-up and it must successfully start with the fix.

Further comments