fix(Experimental): Cross group validation

[ddeskov-limechain]

Add explicit chunk-count validation in from_bytes()

Summary

• Adds an explicit check in Transaction::from_bytes() that rejects multi-group TransactionList payloads for non-chunked transaction types
• Only FileAppendTransaction and TopicMessageSubmitTransaction legitimately use multiple transaction ID groups; all other types now fail early with a clear error message
• Adds regression tests covering both rejection and acceptance paths

Test plan

• cargo test cross_group_forgery -- all 5 tests pass
• cargo test -p hiero-sdk --lib -- full suite (956 tests), 0 failures

[github-actions]

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[gsstoykov]

@rwalworth Could you ignore this PR for now we are experimenting with some tooling.

[rwalworth]

@gsstoykov @ddeskov-limechain just checking in here, would you like to keep this PR open or can we close?

[ddeskov-limechain]

Not relevant.