[msg] Authenticate message before counter and duplicate processing.

[turon]

Problem

Per spec, if a message doesn't self-authenticate, it can be discarded ahead of any counter, replay, or duplicate processing.

Change overview

Performs message decryption/authentication before counter processing as required by specification.

Also renaming SecureMessageCodec::Encode/Decode to SecureMessageCodec::Encrypt/Decrypt to better differentiate crypto processing of a message from more benign header processing and parsing. The initial entry point for message decryption can now be found via regex search for Message.*Decrypt for example.

Testing

Only standard ./gn_build.sh unit test suite.

[github-actions]

Size increase report for "gn_qpg-example-build" from 12a35d8

File	Section	File	VM
chip-qpg6100-lighting-example.out	.text	12	12

Full report output

BLOAT REPORT

Files found only in the build output:
    report.csv

Comparing ./master_artifact/chip-qpg6100-lighting-example.out and ./pull_artifact/chip-qpg6100-lighting-example.out:

sections,vmsize,filesize
.debug_loc,0,56
.debug_line,0,51
.debug_ranges,0,40
.text,12,12
.strtab,0,2
.debug_str,0,1
.shstrtab,0,-2
.debug_info,0,-4
[Unmapped],0,-12

Comparing ./master_artifact/chip-qpg6100-lighting-example.out.map and ./pull_artifact/chip-qpg6100-lighting-example.out.map:

BLOAT EXECUTION FAILED WITH CODE 1:
bloaty: unknown file type for file './pull_artifact/chip-qpg6100-lighting-example.out.map'

[github-actions]

Size increase report for "esp32-example-build" from 12a35d8

File	Section	File	VM
chip-all-clusters-app.elf	.flash.rodata	24	8

Full report output

BLOAT REPORT

Files found only in the build output:
    report.csv

Comparing ./master_artifact/chip-all-clusters-app.elf and ./pull_artifact/chip-all-clusters-app.elf:

sections,vmsize,filesize
.debug_line,0,64
.flash.rodata,8,24
.debug_str,0,2
.strtab,0,2
.riscv.attributes,0,-2
.shstrtab,0,-2
.debug_frame,0,-4
[Unmapped],0,-24
.debug_loc,0,-80

[github-actions]

Size increase report for "nrfconnect-example-build" from 12a35d8

File	Section	File	VM
chip-shell.elf	rodata	16	16
chip-lock.elf	rodata	16	16

Full report output

BLOAT REPORT

Files found only in the build output:
    report.csv

Comparing ./master_artifact/chip-shell.elf and ./pull_artifact/chip-shell.elf:

sections,vmsize,filesize
rodata,16,16
.debug_line,0,10
.debug_str,0,2
.strtab,0,2
.shstrtab,0,-2
.debug_loc,0,-26
.debug_ranges,0,-40
.debug_info,0,-106

Comparing ./master_artifact/chip-lock.elf and ./pull_artifact/chip-lock.elf:

sections,vmsize,filesize
rodata,16,16
.debug_line,0,10
.debug_str,0,2
.shstrtab,0,2
.strtab,0,2
.debug_loc,0,-10
.debug_ranges,0,-40
.debug_info,0,-106