- Moved from reach/ui to material/ui menu components, because reach ui wouldn't work with 2 menus
- This channel selector stores the default on settings
- setActiveChannelIfNotSet was deprecated, if the account has channels, it will always return a channel even if there is no active channel or stored channel
## Issue
??
## Behavioral Changes
- Use `claim_search` instead of `claim_list` to retrieve all all own claims with the same name (case-insensitive).
- Caveat: annonymous posts will be excluded.
- When a clash occurs, there is a possibility that we have multiple existing entries (e.g. "xxX", "xXx"). Since we don't know which one is best to fall back, I removed the "edit" button for this and replaced with a simpler text
## Code Note
- If not mistaken, the rest of the code still needs `selectMyClaimForUri` to be case-sensitive, so augment the selector to support both through an optional parameter.
## Ticket
426
## Issue
Currently, we check if we have any existing claims with the same name when uploading, i.e. "lbry://<name>". It does not include claims that you are still uploading, so you might end up with duplicate claims.
In the ticket, there is also the issue of 2 uploads sharing the same slot, causing the progress indicator to jumpy between the uploads. That has been fixed by using a guid instead of using `name`.
## Aside
I think there is another request to allow the same name but on different channel ... next time, next time ....
---Fixes:
#-2882: "Fix UX around publishing to already published URL".
---Changes:
1. Improved the error message (change color to red; emphasized the URL; tweaked the sentences a bit).
2. The `Publish` button will be grayed out in this scenario, until user explicitly decides to edit existing claim instead.
