Add ability to get list of instructions/lines from the current selection

[kristopax]

What is the feature you'd like to have?
I would like the ability to get the list of instructions/lines associated with the current selection. Based on the instruction type of the current view (e.g. disassembly, IL), the list should contain the appropriate instructions.

Is your feature request related to a problem?
Currently, the current_selection returns a virtual address range in the form of a tuple (start_addr, end_addr). For some ILs, this address range seems to span the (min, max) of the addresses of the instructions contained in the selection, so it's unclear how to get instructions/lines using the address range since the linear view of IL instructions are not always ordered according to virtual address.

[kristopax]

Use ui context to get more information regarding the selection.

[kristopax]

The solution is to expose the m_SelectionStartPos in the Python API.

[xusheng6]

@kristopax How would you expect this to be implemented? Right now there is magic variable current_il_instruction, though it only refers to one instruction, rather than several. Do you want something like current_il_instructions? Besides, do you need this in the C++ API or Python API?