support opening on coordinates via URL's hash

[adbenitez]

this will allow clients to support opening map on POI when user clicks POI messages IN THE CHAT (messages sent from inside the map, the ones that have the location marker in the message bubble)

[adbenitez]

once this is in, the next problem is that core doesn't provide the POI coordinates to the UI/clients, in ArcaneChat I already implemented this in core and I am using a maps app with this patch,

if even I managed to add it to core probably @r10s can do it, here you can see my changes in core: ArcaneChat/core@ba15bba

NOTE: merging this PR doesn't depend on having this ready in core and the UIs

[nicodh]

Looks fine to me, except the input validation of the provided hash values

[adbenitez]

please remember I am not really a web developer, could you explain more precisely what do you mean, or feel free to push/tweak this PR directly as well!

[nicodh]

could you explain more precisely what do you mean

I added a suggestion so all you need to do is click the commit suggestion button :-)

Ah it didn't save for some reason:

[nicodh]

I pushed a commit myself