tools (common/template): add 2 new filters: `timestamp_to_hour` and `delta_to_human`: `timestamp_to_hour` give the hour corresponding to a timestamp, it will be used to display calendar for this time window. `delta_to_human` convert a delta of 2 timestamp to human readable time using `tools.common.date_utils` corresponding function.

[Desktop Entry]
Type=Application
Name=Libervia TUI (Primitivus)
Comment=console frontend for Libervia (XMPP)
Exec=libervia-tui
Icon=org.libervia.LiberviaTUI
Categories=Network;InstantMessaging;Chat;FileTransfer;RemoteAccess;
Keywords=xmpp;chat;messaging;im;file;sharing;communication;jabber;social;network;decentralization;console;