Modify GN to build FreeRTOS from third party source repo

[lucicop]

Problem

• Modify GN script to build FreeRTOS from source code in third party repo

Change overview

• Changes to GN script and libraries to build FreeRTOS from source code

Testing

• Manually tested to compile; ran basic testing involving secure session establishment over BLE, using chip-device-ctrl.

[github-actions]

Size increase report for "gn_qpg-example-build" from e4d15a8

File	Section	File	VM
chip-qpg6100-lighting-example.out	.text	256	256
chip-qpg6100-lighting-example.out	.heap	0	24
chip-qpg6100-lighting-example.out	.bss	0	-8
chip-qpg6100-lighting-example.out	.lower_ram_retain	0	-16

Full report output

BLOAT REPORT

Files found only in the build output:
    report.csv

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'

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

sections,vmsize,filesize
.debug_line,0,831
.symtab,0,416
.debug_str,0,323
.text,256,256
.debug_ranges,0,80
.heap,24,0
.shstrtab,0,-2
.debug_frame,0,-4
.strtab,0,-6
.bss,-8,0
.lower_ram_retain,-16,0
.debug_loc,0,-193
[Unmapped],0,-272
.debug_abbrev,0,-1443
.debug_info,0,-11282