Allow `ENABLED`, `DISABLED`, `PIN_EXISTS`, and `BUTTON_EXISTS` to take multiple arguments. Also add:
- Alias `ANY(...)` for `!DISABLED(...)`
- Alias `ANY_PIN(...)` for `PIN_EXISTS(a) || PIN_EXISTS(b) ...`
- Alias `EITHER(A,B)` for `ANY(...)`
- Alias `ALL(...)` and `BOTH(A,B)` for `ENABLED(...)`
- `NONE(...)` for `DISABLED(...)`

* Multi-nozzle selective duplication
* Use a bit-mask, reduce stepper_indirection.h size
* Tweak the multi-nozzle duplication description
* Use 'S' as a bool in M605
* Add HAS_DUPLICATION_MODE conditional
* Remove '_MODE' from the option name
* M605 in the style of Stacker M280
* Also include direct mask style (P)

* Optimize target_extruder, ignore T with mixing
* Give G-code Tn parity with tool_change

* Apply #pragma once in headers
* Adjust some thermistors formatting
* Misc cleanup and formatting

* Add parser.seen for multiple parameters
* Fix M666, use !seen for report
* Synchronize on M204, M205

- Drop `pgm_read_*_near` and let headers choose.
- Define `USE_EXECUTE_COMMANDS_IMMEDIATE` as a conditional.
- Add `process_subcommands_now` for SRAM-based commands.

* Universal tool-change Z lift
* Add TOOLCHANGE_ZRAISE to example configs
* Park/unpark changes to example configs
* Implement DEBUG_DXC_MODE