- Stepper bugs fixed
- Support MIXING_EXTRUDER with Linear Advance
- Miscellaneous cleanup

- Respect axis max acceleration limits instead of forcing a fixed acceleration value.
- The `junction_unit_vec` ensures proper handling of entry and exit speeds even when the axes involved have different limits.

- Fixed the planner incorrectly avoiding optimization of the block following the active one.
- Added extra conditions to terminate planner early and avoid redundant computations.

Allows the Stepper ISR to wait until a given block is free for use. Allows Planner to plan the first move, which is split into two.

Better encapsulation and considerably reduce stepper jitter

Use macros that explicitly avoid double-evaluation and can be used for any datatype, replacing `min`, `max`, `abs`, `fabs`, `labs`, and `FABS`.

Co-Authored-By: ejtagle <ejtagle@hotmail.com>

Co-Authored-By: ejtagle <ejtagle@hotmail.com>

Fix #10660

Enable 6th-order jerk-controlled motion planning in real-time.
Only for 32bit MCUs. (AVR simply does not have enough processing power for this!)

* Automatically reset stepper timeout in manage_inactivity

Any code that adds moves to the planner can skip resetting the stepper timeout. We can let `idle` / `manage_inactivity` reset the timer whenever it detects any moves in the planner.

* blocks_queued => has_blocks_queued

From #9914 by @Sebastianv650

Also remove unused grid slicing function when using UBL segmented.

* repair reverse_pass()

And make it readeble.
This was broken a long time ago.
Not competely unfunctional but far from optimal.

* Minor speedup when calling calculate_trapezoid_for_block

2 float / to 1 foat / and 2 float *

* Various style changes

While homing or probing it might be bad if the stop/trobe triggers during the first part and the second is still in the buffer.

This reverts commit 824980e70e, reversing
changes made to aa7efb96bf.

Address #8573, #8595