Improve ARM features detection

[Dr-Noob]

Current features detected under ARM are not always relevant, and probably there are relevant features that are not shown (e.g, #130).

A list of relevant features should be elaborated and the program should be updated accordingly.

[Dr-Noob]

Another related issue is in get_features_info where it is assumed that all cores share the same capabilities, which probably is not.

[Dr-Noob]

This shows that not all ARM cores have 1 SIMD unit. It is also worth noting that NEON includes FMA, which is not considered in the current cpufetch code

[Dr-Noob]

This suggests a better implementation for (at least) fetching the MIDR.

[Wunkolo]

Oaknut, the ARM64 emitter, also has some expansive detection of processor features across different operating systems and platforms that could be a good reference:

https://github.com/merryhime/oaknut/tree/6b1d57ea7ed4882d32a91eeaa6557b0ecb4da152/include/oaknut/feature_detection

[Dr-Noob]

Oaknut, the ARM64 emitter, also has some expansive detection of processor features across different operating systems and platforms that could be a good reference:

https://github.com/merryhime/oaknut/tree/6b1d57ea7ed4882d32a91eeaa6557b0ecb4da152/include/oaknut/feature_detection

They use getauxval as far as I can tell (which it's the same I use). I don't think there is much more ways to do it.

I've had in mind for a long time to remove all features but NEON, and also check how to find if the CPU supports SVE and/or SME, which would be the "equivalent" to the features shown in the x86 version. Maybe also renaming it to "Vector extensions", e.g., go from:

Features: NEON, SHA1, SHA2, AES, CRC32

to

Vector extensions: NEON, SVE, SME

Another thing I have in mind is to show the ARM version (This is already implemented but not simply not shown). I don't know which title to use or if it should be merged into another line.

I think I'll implement all these ideas for the upcoming cpufetch release.