fix: adjust the popup direction of combobox to adaptive

[pigeoner]

System information for bug reporting and debugging

System	: Windows 11 Version 23H2
CPU	: x86_64
Kernel	: winnt-10.0.22631
ABI	: x86_64-little_endian-llp64
WSRX	: 0.2.31.g195a598
Machine	: LAPTOP-5HC8OVNN-cb79d211-728d-4bbb-b01d-c7f676d5c40d

Description

Original

When clicking on combobox, it will first attempt to pop up menu items downwards. If there is not enough space below, it will switch to popping up upwards, which will cause a slight flicker.

1.mp4

Modification plan

• First calculate the distance between the current combobox and the bottom of the window.
• If it is greater than the height of the pop-up box, it will pop up downwards.
• Otherwise, it will pop up upwards

2.mp4

[Reverier-Xu]

Thanks for the improvement!