Observed bugs on Polybuilder on Actual

Note: test.glycam.org was down when these observations were made. Before making any edits, confirm that the issues still remain in the latest codebase.

https://jam.dev/c/81f1057c-8936-45fc-af11-fc939dcc032f

- [x] Node panel allows users to enable buttons that are disabled, simply by clicking the enabled option.
- [x] Linkage picklists don't allow users to move forward if they want to accept the defaults. This is because the event that is listened for is onchange. One solution is to set the default to a label that no one should be allowed to pick, such as "Alpha Linkages" and "Beta Linkages". Try that and see what people think. There may be other solutions so keep an open mind.
- [x] It is possible to submit a sequence that contains "..."