Improvements for the build via text page

https://jam.dev/c/98567099-8242-4892-82a8-806199df0ece

Summary:
brave (chrome) copies and pastes sequences ok. Does not work the same in firefox where I get extra spaces at the beginning of the copied string.

Two suggestions:

- [x] Remove any spaces from the start and the end, but not the middle of sequences.
- [ ] Add a button to click beside each example sequence that allows me to directly inject the sequence into the text box. (Do not submit that sequence automatically as I may want to edit it.)