refactor(shell): Improve shell command naming and output formatting

- Renamed shell commands in  and  to be shorter
  and remove underscores (e.g.,  to ).
- Consolidated get functions into a single show command for both valve
  and Modbus settings (e.g., , ).
- Adjusted output formatting for show commands to be right-aligned and
  remove horizontal lines for better readability.
- Fixed missing getter function implementations in  and their
  declarations in .
- Ensured  is correctly selected in
  to make valve shell commands available.

software/lib/shell_valve/CMakeLists.txt

@@ -1 +1 @@
-zephyr_library()
+zephyr_library_sources(shell_valve.c)