Add json marshalling tests for action usage and OIDC types

[rameshgkwd05]

This PR covers JSON marshalling testing for following types (partial fix for #55)

1. actions_oidc

   1. type OIDCSubjectClaimCustomTemplate

2. actions_cache

   1. type ActionsCache
   2. type ActionsCacheList
   3. type ActionsCacheUsage
   4. type ActionsCacheUsageList
   5. type TotalCacheUsage
   6. (type ActionsCacheListOptions does not have any json encoding so we have skipped test case for it.)

NOTE for reviewers: This contribution is for hactoberfest credit please label it so. Thanks!

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[rameshgkwd05]

updating github user email and reopening another PR