[VOCAB]: Add URI option

[mafragias]

Create an extra option to the reconciliation process. A user needs to be able to add a URI instead of just having only the current presented options of generating a pharos URI or matching it with some of the suggested options.

• Create a field (@mafragias)
• Add the functionality in template (@AndreasMichelakis)

[mafragias]

Created option to give new URI :

Could you @AndreasMichelakis prettify it ?

[AndreasMichelakis]

@mafragias This was done for both ULAN and WikiData buttons:

[lklic]

Implemented