🍁 Cache update for private data members + New Unit Test suite

[akashchouhan16]

Changelog

1. Make all data members private.
2. Access to private cache map disabled. i.e cache.cache is not allowed. The cache is only exposed via the getters and setters.
3. Updated Configuration setup code change. Cache.config is get only for an instance and it is only exposed via getCacheConfig() api.
4. Logger configurations are private and only exposed via getLogConfig() api.
5. Code refactor. Removed bad code and updated unit test cases.

[github-actions]

Coverage report

St.❔	Category	Percentage	Covered / Total
🟢	Statements	92.82% (+1.15% 🔼)	530/571
🟡	Branches	79.85% (-0.3% 🔻)	107/134
🟢	Functions	97.14% (+0.24% 🔼)	136/140
🟢	Lines	92.69% (+1.2% 🔼)	520/561

Show new covered files 🐣

St.❔	File	Statements	Branches	Functions	Lines
🟢	... / nodecache.configsetup.test.js	100%	100%	100%	100%

Show files with reduced coverage 🔻

St.❔	File	Statements	Branches	Functions	Lines
🟢	src/nodecache.js	86.61% (+0.76% 🔼)	89.25% (-0.75% 🔻)	82.35% (+2.35% 🔼)	86.61% (+0.76% 🔼)

Test suite run success

65 tests passing in 3 suites.

Report generated by 🧪jest coverage report action from 0b2d81c