Introduces new memory allocation functions, based on wled#4895 by @DedeHai
* keep a minimum of 15KB RAM available to UI - improves stability
* S3/S2/C3 automatically use "fast RTC Ram" for small data (reduces fragmentation)
* auto-detects PSRAM (or no PSRAM) when firmware was built with -D BOARD_HAS_PSRAM
* d_malloc() and d_calloc() prefer DRAM if possible (faster), but fall back to PSRAM when free RAM gets low.
* reduce JSON buffer from 1024 to 640
* ESP32: define buffer globally (reduces likelyhood of crashes due to low stack)
* added some sanity checks after string ops
* delete hueClient object after closing the connection
* make functions static if not used outside of hue.cpp, re-shuffle order where needed
* rename JSON buffer object: root -> jsonHUEroot
WLED-MM backport of upstream wled#4980
RMT High-priority Interrupt driver - solves flickering problems on esp32, esp32-S2 and esp32-S3
do not use the new RMTHI driver on old V3 builds (especially esp32dev_compat)
upgrade all esp32 builds to NeoPixelBus 2.7.9 (we can't go higher due to API incompatibilities)
* separate mutexes for improved performance:
- busses.show and effect drawing
- critical changes to segment vector
- block out critical segment changes while strip.service() loops over segments
* UDP realtime acquires mutex before drawing
- prevents corrupted outputs, caused by parallel tasks updating pixels while busses.show() runs
revised mutex and critical section handling for segment drawing
- simplified code with macros (no more #if ESP32 ... #endif)
- remove some critical sections (prevents interrupt stalling)
- added mutex to functions that change the list of segments
- added mutexes to all (potential) background drawing code
- use recursive mutexes to prevent accidental self-locking of tasks
* protect pixel buffer changes with critical section
* protect segment list modification with critical section
* make _isServicing and _triggered atomic (move out of packed bitarray)
* allow custom timeout for waitUntilIdle - DDP needs a longer timeout
* protect strip.show() and effect drawing functions with mutex, to prevent crashes
* enable ARDUINOJSON_DECODE_UNICODE (otherwise unicode needs 6(!) bytes for encoding)
* robustness: increase a few tiny string buffers for some extra margin
* Web UI: allow entering up to 64 chars as segment name
* mark synchronization variables volatile (thread-safe)
* additional logic in closeFile() to avoid file write while leds are pushed out by NPB driver
* some comments and analysis
* replace "yield()" after file ops with "delay(0)" before operations.
* use a more meaningful max universes limit of 112 (safe up to 128x128 pixels)
* accept more universes, but only track sequences for the configures max universes
* made e131LastSequenceNumber[] local (its only used in e131.cpp)
