remove stringifyTmpl and stringify from LayerArrayFieldTemplate

Remove both deprecated functions and then get rid of squirrelly which should not be necessary anymore. Make sure to clean up the vite config on demo afterwards. Make sure that this deletion won't affect existing forms in CAP. Update them first if necessary.

Start at LayerArrayFieldTemplate and locate the deprecated stringifyTmpl and stringify functions, then inspect the demo Vite configuration for remaining squirrelly setup. Check the existing CAP forms before deleting the functions, update them if needed, and verify that the forms still work after the cleanup.

Written by the indexing model from the issue text.