Pr fft

[AsiiaPine]

This PR adds rfft algorithm for both ubuntu version and stm32 version. Real fft was borrowed from public libraries:

• for stm32 --- CMSIS-DSP
• for ubuntu fftw3 installation script. The version is used for unit tests

Firmware image size difference

• dronecan_v2: ? -> ? (+?)
• dronecan_v3: ? -> ? (+?)
• cyphal_v2: ? -> ? (+?)
• cyphal_v3: ? -> ? (+?)

Test coverage

• In SITL...
• With real device...

[sonarcloud[bot]]

Quality Gate passed

Issues
67 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[PonomarevDA]

Is it a duplicate of #74? Should we close it?