Added check for CSCwo96334: /tmp directory disk space for snapshot storage

[Harinadh-Saladi]

1. Added tmp_dir_snapshot_storage_check to validate /tmp space before upgrades < 6.1(4a)
2. Check monitors F1527/F1528/F1529 faults on /tmp mount point only
3. Returns FAIL_UF if /tmp disk space issues found, NA for versions >= 6.1(4a)
4. Added 18 comprehensive test cases covering affected and fixed versions
5. Added test fixtures for positive, negative, and mixed fault scenarios
6. Updated validations.md with check documentation and bug reference CSCwo96334"

Have tested both positive and negative scenarios and enclosed the logs for the same.

CSCwo96334_Pytest_Logs.txt

CSCwo96334_Fail_Scenario_Logs.txt