hotfix(frontend): Consistent buttons and their styles throughout the app

[amanape]

Brand buttons now support a custom startContent that accepts react nodes

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Link of any specific issues this addresses

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To run this PR locally, use the following command:

docker run -it --rm   -p 3000:3000   -v /var/run/docker.sock:/var/run/docker.sock   --add-host host.docker.internal:host-gateway   -e SANDBOX_RUNTIME_CONTAINER_IMAGE=docker.all-hands.dev/all-hands-ai/runtime:ede4c55-nikolaik   --name openhands-app-ede4c55   docker.all-hands.dev/all-hands-ai/openhands:ede4c55

[rbren]

@amanape I still see a lot of inconsistency in the blue and gray backgrounds

[rbren]

I think mainly on the settings page

[rbren]

@amanape let's standardize on the blue, I think it looks better with the yellow

[amanape]

This PR is actually more buttons-only; bg color consistency is handled in #6833

[rbren]

I think we lost the vscode logo

[rbren]

@amanape let's do both in the same PR, otherwise it feels inconsistent

[rbren]

VS code logo shot

[amanape]

@rbren I've removed the VSCode logo and the GitHub logo - should I keep both?

[rbren]

Why not keep them?

[rbren]

Yeah I think they look better with the logos there

[amanape]

Why not keep them?

Consistency reasons - didn't think much of it. Will add them back 👍