fix: execute script mode IF and Python helpers

[kocaemre]

Summary

• Remove the duplicate stub _dsl_if implementation so DSL IF blocks use the existing block-aware control-flow handler.
• Skip false DSL branches to the first statement after ELSE, and skip ELSE bodies after a true branch.
• Queue and await Python-mode CALL/EMIT helper tasks so plain scripts like CALL(...) and EMIT(...) actually execute.
• Add regression coverage for DSL IF/ELSE, Python CALL, and Python EMIT.

Fixes #50.

Test plan

• Confirmed new regression tests failed before the implementation:
  • test_dsl_if_false_skips_to_else_branch
  • test_python_call_helper_executes_device_action
  • test_python_emit_helper_executes_event
• python3 -m pytest tests/logic/modes/test_script_mode_logic.py -q — 6 passed
• python3 -m pytest tests/logic/modes -q — 76 passed, 4 existing warnings
• python3 -m pytest tests/logic -q — 563 passed, 1 skipped, 20 existing warnings
• python3 -m py_compile custom_components/opengrowbox/OGBController/managers/OGBScriptMode.py tests/logic/modes/test_script_mode_logic.py
• git diff --check