Fixes #1458 - Incorrect display of free mem on statistics page
lcd_outdezNAtt() on ARM was casting values to uint16_t.
Re #1458 - the cast is back, but cast to different type depending on platform. Gtest modernized.
Re #1458 - Forgoten files for new gtest
Re #1458 - added gtest for big numbers (>uint16_t)
Fixes #1458 - 64k was hardcoded
Merge pull request #1460 from opentx/projectkk2glider/issue_1458

Fixes #1458 - Incorrect display of free mem on statistics page
Fixes #1451
Fixes #1461
Fixes #1458
Re #1457 - added display of channels 17-32 to Companion simulator
Fixes #1392
Curves in Mixes were not correctly restored on Companion for Sky9x
boards
Fixes #1463
Fix warnings with libpng
Merge origin/next into next
Fix warnings with libpng
Re #1464 - added test: "L1  Vfas < 9.6 Delay (0.5s)"
Fixes #1451
Re #1443 - Reverting back d675ab157893770116dc158efe58573f3dd04f4a with some improvements:
* when telemetry is not streaming all logical switches that involve telemetry value evaluate to FALSE (same as before the change in above commit)
* the duration and delay processing is now enabled for such logical switches (new functionality that was not present before above commit)
Gtests split into several source files