## Issue
Closes 5687: Ensure post mode has no text limit
## Changes
- `type="markdown"` can now have unlimited length if clients don't define `textAreaMaxWidth`.
- The internal default limit of 2000 is narrowed down to `type=textarea`.
## 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.`