Integrate other PRs for fixing extensions

[PhilipFackler]

Using backend struct tags like #62 (following KernelAbstractions) and backend dispatch from #118 so we don't overwrite names. Addresses #122

[PhilipFackler]

Test this please

[williamfgc]

Test this please

[williamfgc]

Test this please

[williamfgc]

Hi @PhilipFackler please feel free to rebase main, resolve conflicts and test again. Let's see if PR #126 fixes the issue with AMD GPU CI. Thanks for the effort.

[PhilipFackler]

Test this please

[williamfgc]

Great work @PhilipFackler just a couple of things:

1. AMDGPU CI is failing due to dependencies in KA?
2. We should sync up on CI code formatting using JuliaFormatter.jl

[PhilipFackler]

Test this please

[PhilipFackler]

Test this please

[PhilipFackler]

Test this please

[williamfgc]

@PhilipFackler the AMDGPU.jl version is restricted to > 1.0 . Should we try 0.8 in JACC's Project.toml ? @jpsamaroo any ideas of the failure on CI AMD GPU deps ?

[PhilipFackler]

@PhilipFackler the AMDGPU.jl version is restricted to > 1.0 . Should we try 0.8 in JACC's Project.toml ?

We had 0.8 in both the Project.toml and in runtests.jl. I was trying to see if updating it would make a difference with the error we're seeing. I need to just get on an AMD system and run it myself. I wasn't able to login to cousteau today. I'll try again later this week.

[PhilipFackler]

Test this please

[PhilipFackler]

Test this please

[williamfgc]

Merges and closes #118, #114, #86, #62