Improve resolving non-code addresses

[bjoernQ]

This improves how we resolve non-code addresses.

Before

load:0x40080400,len:4
0x40080400 - _DoubleExceptionVector
    at ??:??
ho 8 tail 4 room 4
load:0x40080404,len:3876
0x40080404 - _DoubleExceptionVector
    at ??:??
entry 0x4008064c
0x4008064c - __user_exception
    at C:\Users\Bjoern\.cargo\registry\src\index.crates.io-6f17d22bba15001f\esp-backtrace-0.11.0\src\lib.rs:130

After

load:0x40080400,len:4
ho 8 tail 4 room 4
load:0x40080404,len:3876
entry 0x4008064c
0x4008064c - __user_exception
    at C:\Users\Bjoern\.cargo\registry\src\index.crates.io-6f17d22bba15001f\esp-backtrace-0.11.0\src\lib.rs:130

__user_exception is still confusing but at least it's the same result as xtensa-esp32-elf-addr2line

[bjoernQ]

@SergioGasquez I remember you looked into that openssl build problem before?

[SergioGasquez]

@SergioGasquez I remember you looked into that openssl build problem before?

Yes, feel free to ignore it for the moment. See #602 and #597

[MabezDev]

Nice this is much nicer! FYI this now brings the output inline with idf's monitor program, it prints the __user_exception (under a different name though), so I think this is the best we're going to get right now.