[DDW-1114] Message for current stake pool being selected again

[tomislavhoracek]

This PR introduces a new message for the current stake pool being selected again and Improved delegation wizard start step logic.

Screenshots

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Testing Checklist

• Slack QA thread
• Test that delegation wizard always starts from "Intro" step. Both from stake pools list and delegation center
• Delegate not delegated wallet and pay attention to checking / checked stake pool
• Delegate already delegated wallet and pay attention to checking / checked stake pool. Delegated stake pool should be visible but with opacity and not selected. If you select that stake pool then next step is disabled and a new message near the selected pool is displayed (You are already delegating Darko’s ada wallet to [XGSS] stake pool. If you wish to re-delegate your stake, please select a different pool.) - that is the case if you started the delegation wizard from delegation center. if you start a delegation wizard from stake pools list and you select stake pool and wallet that is delegated to that stake pool, on 3rd step (Choose stake pool) stake pool should be selected but the next step is a disabled and same message shown.

Copy: https://docs.google.com/document/d/1_rN4iXg739sngWsuaN9oCAjs1cQvIUCKONrjhfYu3QM/edit

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Review Checklist

Basics

• PR has been assigned and has appropriate labels (feature/bug/chore, release-x.x.x)
• PR is updated to the most recent version of the target branch (and there are no conflicts)
• PR has a good description that summarizes all changes and shows some screenshots or animated GIFs of important UI changes
• CHANGELOG entry has been added to the top of the appropriate section (Features, Fixes, Chores) and is linked to the correct PR on GitHub
• Automated tests: All acceptance and unit tests are passing (yarn test)
• Manual tests (minimum tests should cover newly added feature/fix): App works correctly in development build (yarn dev)
• Manual tests (minimum tests should cover newly added feature/fix): App works correctly in production build (yarn package / CI builds)
• There are no flow errors or warnings (yarn flow:test)
• There are no lint errors or warnings (yarn lint)
• There are no prettier errors or warnings (yarn prettier:check)
• There are no missing translations (running yarn manage:translations produces no changes)
• Text changes are proofread and approved (Jane Wild / Amy Reeve)
• Japanese text changes are proofread and approved (Junko Oda)
• UI changes look good in all themes (Alexander Rukin)
• Storybook works and no stories are broken (yarn storybook)
• In case of dependency changes yarn.lock file is updated

Code Quality

• Important parts of the code are properly commented and documented
• Code is properly typed with flow
• React components are split-up enough to avoid unnecessary re-renderings
• Any code that only works in main process is neatly separated from components

Testing

• New feature/change is covered by acceptance tests
• New feature/change is manually tested and approved by QA team
• All existing acceptance tests are still up-to-date
• New feature/change is covered by Daedalus Testing scenario
• All existing Daedalus Testing scenarios are still up-to-date

After Review

• Merge the PR
• Delete the source branch
• Move the ticket to done column on the YouTrack board
• Update Slack QA thread by marking it with a green checkmark

[nikolaglumac]

Great work @tomothespian 💯

[IuliaDolishniak]

@tomothespian please forgive if this one is not connected to the current PR but I am experiencing the following issue, may be it is connected to the #1754