Use blend instead of set and extract to rearrange, faster
Use 256 SIMD for every 2 RB, use 128 SIMD for ARM and last RB

Testing on Neoverse N1 (Ampere 3GHz). Tested only on a subset of phy-simulators.

- Changes:
- use SIMDE consistently
- adaptations of LDPC decoder generator for ARMv8 performance
- SIMDe modifications of Intel CRC to allow for aarch64 build.
  optimizations for 128-bit to improve performance of LDPC encode/decode
  on aarch64 (Neoverse 1)
- added BG2 files for 128-bit ldpc encoder (aarch64)
- testing on Xeon
- testing on x86
- minor changes to build/run on x86
- change in crc.h after returning to aarch64
- removed some warning in ldpc decoder generator for x86_64
- char
- Delete irrelevant constants
- Correctly declare variables
- Define stdbool for all architectures
- Remove definition of _MM_SHUFFLE and use SIMDE_MM_SHUFFLE
- Remove commented code
- Fix CMakeLists.txt
- Include SIMDE avx2 functions in tools_defs.h

fix the 64QAM modulator case, that process 192 bits per iteration, then 24 bits per iteration of the tail bits, then added the last two symboles processing (no odd number of symbols case)

1. Adding a "SL" frequency for Sidelink mode. The
   importance of this variable is to ensure that
   when we are in mode 1 (UE+UE+gNB), that the slot
   configuration and frequencies do not overlap. This
   SL frequency is important for rotation and allows
   us to utilize the OFDM modulation and demodulation
   functions that already exist in OAI.
2. Adding sl_mode to the command line for proper UE
   deployment when in SL mode. sl_mode can be set to 0,
   1, or 2. sl_mode 0 indicates no-Sidelink at all,
   mode 1 is gNB, UE, and UE (3GPP defines mode numbers).
   sl_mode 2 indicated UE to UE communications with no
   gNB at all.
3. New functions for calculating the carrier frequency
   for SL mode.

Only Ncp1 is used, so get rid of the second timeshift_symbol_rotation array.
Also simplify the computation of "t0 * Tc * f".

for gNB its in L1 section of config file
for UE its a cmd line paramenter

also fixed build wanings

This is necessary to compensate the rotation caused by the timeshifted OFDM symbol (1/8 CP)

- now done according to the proper DL/UL frequency
- this makes it compatible with FDD mode

This commit contains work done by Eurecom and by Benetel.

implementation of missing symbol-based rotation for NR modulation/demodulation (Section 5.3 38.211). Tested with unitary simulators (ulsim/dlsim).
To be tested with gNB testbench and rfsimlator