Switch from SweetAlert to SweetAlert2

[limonte]

I would like to propose to switch from SweetAlert to SweetAlert2 - the supported fork of SweetAlert. The original reason for creating SweetAlert2 is inactivity of SweetAlert: https://stackoverflow.com/a/27842854/1331425

Documentation for SweetAlert2: https://sweetalert2.github.io/

Reasons to switch:

1. Accessibility (WAI-ARIA) - SweetAlert2 is fully WAI-ARIA compatible and supports all popular screen-readers. Accessibility is a must in 2020, there are a lot of explanatory and tech articles, but this one is truly inspirable: Software development 450 words per minute

2. Better support, average time to resolve an issue:

   • SweetAlert:
   • SweetAlert2:

3. SweetAlert2 is far more popular and battle-tested that SweetAlert:

   • SweetAlert:
   • SweetAlert2:

4. SweetAlert2 is dependency free, SweetAlert has 2.

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Also removed the package-lock.json file per Yarn's recommendation:

warning package-lock.json found. Your project contains lock files generated by tools other than Yarn. It is advised not to mix package managers in order to avoid resolution inconsistencies caused by unsynchronized lock files. To clear this warning, remove package-lock.json.