_lv_area_is_in() function
Check if an area is fully on an other
Arguments
ain_p
pointer to an area which could be in 'aholder_p'
aholder_p
pointer to an area which could involve 'ain_p'
radius
radius of `aholder_p` (e.g. for rounded rectangle)
Return value
true: `ain_p` is fully inside `aholder_p`