feat: Indent fixes

Formatting-only follow-up: generator templates emit less-nested code now that try/catch was removed (#915), so template indentation is corrected to keep generated `.java` properly formatted. No functional change.

**Benefit:** keeps generated source readable/lint-clean after the exception-removal refactor.

PR: hashgraph/pbj#916

Start by reviewing the generator templates and the exception-removal changes in #915, then compare the formatting follow-up described in #916. Done means generated .java source is less nested, properly indented, readable, and lint-clean without functional changes.

Written by the indexing model from the issue text.