more improvements, fix url, do the same for cover
remember url, error if invalid
unneeded addition
Fix delayed message
Lint
Allow empty values (placeholder and Gerbil)
Fix filepath crash
Fix button
* Automatically claim initial rewards (new_user & email_verified) when accessing creating channel, edit channel and upload
* Do not try to get initial rewards if already claimed.
## Changes:
1) TagSearch: hide the "control tags" in the Creator Settings page (irrelevant).
2) TagSearch: show the "control tags" when creating/editing Channel (let's use `setting.CommentsEnabled` instead).
3) TagSearch: show the "control tags" when creating/editing Content (`disable-comments` can be used to block comments at the per-claim level, e.g. allow comments in general but block only for specific claims).
## Missing pieces:
For (2) and (3), some work is needed to hide the comment GUI when `setting.CommentsEnabled` is disabled for a particular channel. That flag is not ready in Commentron yet, so I'm not sure how this will be done at the moment. In other words, the checkbox does nothing at the moment.
## Potential flaw:
This change will hide all control tags. If we have more tags in the future and would like to selectively disable some, we'll have to change this parameter to an array instead. Since the usage is not widespread at the moment, a single `disableControlFlag` seems cleaner (don't over-think it yet).
## Issue
Second attempt at 5571: Limit description length on channel edit
## Changes
- Undo #5573: restore limit back to 5000.
- Translate the `bad-txns-claimscriptsize-toolarge (code 16)` error into `Transaction limit reached. Try reducing the Description length.`
