2D corner collision issue

[subtyven]

Godot version:
3.1

OS/device including version:
Windows 10

Issue description:
If you create a wall composed of multiples shapes, with tilemap for example, and then you hit the intersection between 2 shapes with a ball, the physics engine will considere that the ball should bump in a corner, even if the corner is filled by the adjacent shape.

This basically makes some 2D ball based games impossible to create.

Steps to reproduce:
Just run the project below with collision shapes visible

Minimal reproduction project:
https://github.com/sollidsnake/godot-corner-collision-issue

[KoBeWi]

Related to #32182 (probably)

[subtyven]

Related to #32182 (probably)