Welcome screen and SetupAssistant changes

[SpecialAro]

Pre-flight Checklist

1. Please remember that if you are logging a bug for some service that has stopped working or is working incorrectly, please log the bug here
2. If you are requesting support for a new service in Ferdium, please log it here
3. Please remember to read the self-help documentation - in case it helps you unblock yourself for issues related to older versions of recipes that were installed on your machine. (These will get automatically upgraded when you upgrade to the newer versions of Ferdium, but to get new recipes between Ferdium releases, this documentation is quite useful.)
4. Please ensure you've completed all of the following.

• I have read the Contributing Guidelines for this project.
• I agree to follow the Code of Conduct that this project adheres to.
• I have searched the issue tracker for a feature request that matches the one I want to file, without success.

Description of Change

• Convert several files from js to jsx and fix lint
• Add back buttons on Login, Signup and Select Server pages - removed the previous text.
• Add ability to skip adding recipes after Signup (in SetupAssistant)
• Change default to no recipe selected when in SetupAssistant screen

Motivation and Context

There was a need of a cleaner UI with back elements and also a skip button on Setup Assistant screen.

Screenshots

Welcome Screens

Login	Signup	Change Server

SetupAssistant Screen

Checklist

• My pull request is properly named
• The changes respect the code style of the project (npm run prepare-code)
• npm test passes
• I tested/previewed my changes locally

Release Notes

Welcome screen and SetupAssistant changes

[vraravam]

Love it!!!