* Recently the prototypes for the application hook functions were
moved out of the kernel .c files and into the .h files. That
changes results in compile time warnings for projects that provide
hook functions with a slightly different prototype - in particular
where signed char * is used in place of just char * as an older
FreeRTOS coding convention required chars to be explicitly qualified
as signed or unsigned.
This checkin fixes the warnings by ensuring the signature of
implemented hook functions matches the signature of the prototypes.
* Updated indentation in AVR_ATMega4809_Atmel_Studio and AVR_Dx_Atmel_Studio projects, plus small fixes in their readme files.
* Added AVR_ATMega4809_IAR, AVR_ATMega4809_MPLAB.X, AVR_Dx_IAR and AVR_Dx_MPLAB.X demo projects.
* Removed build artefacts and added .gitignore files in AVR_ATMega4809_MPLAB.X and AVR_Dx_MPLAB.X projects.
Co-authored-by: Yuhui Zheng <10982575+yuhui-zheng@users.noreply.github.com>