tests/ftests: cover cpu.uclamp.min/max passthrough abstractions

tests/ftests: cover cpu.uclamp.min/max passthrough abstractions

Extend sudo cgxset/cgxget cpu conversion tests (069/070) with uclamp
min/max checks across v1 and v2 conversion paths.

Rows are optional and skipped only when the kernel does not expose the
requested uclamp file, preserving compatibility on older environments.

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tom Hromatka (Oracle) <tom.hromatka@gmail.com>