Add dynamic calls as cli arguments

[paulwuertz]

Enables the user to add dynamic calls like callbacks to the call graph.

Closes #105.

Add the funcion call from func_a calling func_1 by --add-dynamic-calls 'func_a->func_1'.

An example the cannectivity firmware based on zephyr.

It has a driver abstraction calling the chip-specific driver layer, which then calls a user given callback function. In the images below user_callback and driver_implementation have both no callers(1), as they are inserted as function pointers to some structs at runtime. The os_interface function has 3 callees. The worst case max stack recognized for the gs_usb_tx_thread is 712 bytes where the call tree goes up to the os_interface z_impl_can_send and the callback worst case stack usage is 488 bytes(2).

user_callback	driver_implementation	os_interface

When adding the 3 dynamic calls os_interface->driver_implementation->user_callback as arguments:

• --add-dynamic-calls "z_impl_can_send->can_mcan_send"
• --add-dynamic-calls "can_mcan_send->gs_usb_can_tx_callback"

puncover --elf_file ~/git/cannectivity/build/zephyr/zephyr.elf --build_dir ~/git/cannectivity/build/  --add-dynamic-calls "z_impl_can_send->can_mcan_send" --add-dynamic-calls "can_mcan_send->gs_usb_can_tx_callback"

Then we get user_callback and driver_implementation having one caller (3) getting called from z_impl_can_send (4) and all are in the same worst stack path with now using up to 856 bytes.

user_callback	driver_implementation	os_interface

With the open PR #106 for the conig file it looks like this:

elf_file: ~/git/cannectivity/build/zephyr/zephyr.elf   
build_dir: ~/git/cannectivity/build/
add-dynamic-calls: [
    z_impl_can_send->can_mcan_send,
    can_mcan_send->gs_usb_can_tx_callback,
]