Use shipped version of Vue

[marijnvanwezel]

MediaWiki now ships with Vue 3 by default. However, WikiSearchFront has vue as an explicit dependency. This should be changed so that WikiSearchFront uses the version shipped with MediaWiki.

• Make the codebase compatible with MediaWiki's Vue 3. It should be noted that there are some differences between normal Vue 3 and MediaWiki's version, which may cause some problems!
• Remove the explicit vue dependency.
• Remove the dist folder containing build artifacts.
• Test on MediaWiki 1.39 (Vue 3 with compatibility layer) and on MediaWiki 1.43 (Vue 3).

See also: https://www.mediawiki.org/wiki/VueJS