Updates to the template/goal feature (#588)

* Dedupe loot-core webpack configs

* Swap to parsing using Peggy

* Actually record syntax errors

* Refactor template types

* Add notifications after applying the templates

* “Successfully”

* Try a Nearley grammar

* Revert "Try a Nearley grammar"

This reverts commit 1e11c07b855a492b905f1291c3eadd93f78ac3de.

Not going with this approach since the error messages are inscrutable.

* switch to PEG.js which has slightly better tooling support

* fix parser

* Fix error reporting

* Adjust grammar for better error messages

Also allow spaces between currency symbol and number

* Fix grammar

* Make #template prefix case insensitive

* Trailing commas

* Remove patch-package from loot-core