shell: introduce `shell_xxx_impl` wrapper functions for output macros

Refactor shell output macros to minimize caller overhead by eliminating
direct `color` parameter passing:
- Introduce wrapper functions: `shell_info_impl`, `shell_print_impl`,
  `shell_warn_impl`, `shell_error_impl`.
- Replace `shell_fprintf` in macros with these new wrappers.
- Update `shell_hexdump_line` to use the new wrappers,
  minimizing caller overhead.

Signed-off-by: Pisit Sawangvonganan <pisit@ndrsolution.com>