[TO REFINE] Show an alternative label for properties

[jmformenti]

For some properties, it would be interesting to show an alternative label in the PBUI.

Implementation tips

• Use i18n to define alternative labels, for example, in lang/en.js:

  export default {
  ...
  properties: {
  P476: 'My alternative label',
  P34: ...
  ....
  ....

• When showing the label for a property, first check if an alternative label is defined using te method from i18n: https://stackoverflow.com/a/62602121. If not, show the default label from wikibase.