libobs/graphics: Add support for param assign with type constructor

[exeldro]

Description

Add support for:
uniform float4 test = float4(1,0,0,1);
next to the existing:
uniform float4 test = {1,0,0,1};

Motivation and Context

Support more shader stuff. This helps converting glsl shaders more easily.

How Has This Been Tested?

On windows 11 by having a shader with the new param assignment

Types of changes

• Tweak (non-breaking change to improve existing functionality)

Checklist:

• My code has been run through clang-format.
• I have read the contributing document.
• My code is not on the master branch.
• The code has been tested.
• All commit messages are properly formatted and commits squashed where appropriate.
• I have included updates to all appropriate documentation.

[PatTheMav]

Can you post an example shader to test this with? I need to ensure this doesn't break Metal shader transpilation.

[exeldro]

for example in

obs-studio/libobs/data/solid.effect

Line 2 in 2b613f4

uniform float4 color = {1.0, 1.0, 1.0, 1.0};

replace {1.0, 1.0, 1.0, 1.0} with float4(1.0, 1.0, 1.0, 1.0)