[Snippets] SplitLoops: inner loops splitting support (#32008)
### Details:
- *SplitLoops: added an ability to split inner loops after the most
outer loop splitting. Currently, there is a limitation: internal loops
can be split only if the inner loop has no tail iteration. To remove
this limitation, it's necessary to modify InsertSpecificIterations logic
-- this should be done in follow-up PRs*
- *InsertSpecificIterations: fixed the case of cloning the ports which
are outside the loop*
### Tickets:
- *CVS-113755*
- *CVS-172631*
### Prerequisites:
- #32057
- #32177
- #32209
- #32305
