Bump vue-router to version 5

[jacobg]

Currently, Ionic is pinned on vue-router version 4 here:

ionic-framework/packages/vue-router/package.json

Line 66 in c88c0de

"vue-router": "^4.0.16"

and here:

ionic-framework/packages/vue/package.json

Line 68 in c88c0de

"vue-router": "^4.0.16"

vue-router version 5 has been out for 4 months already, and Ionic should bump to it:
https://www.npmjs.com/package/vue-router?activeTab=versions

P.S. Bumping vue dependency to version 3.5 would also be great! 😄