fix: Add social login buttons to signup screen

[mirovladimitrovski]

Description

This PR solves #OWA-72. Also #SERV-15341

Steps completed:

According to our definition of done, I have completed the following steps:

• [x] Acceptance criteria met
• [ ] Unit tests added
• [ ] Docs updated (including config and env variables)
• [ ] Translations added
• [x] UX tested
• [x] Browsers / platforms tested
• [x] Rebased & ready to merge without conflicts
• [x] Reviewed own code

[github-actions[bot]]

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