Qt: "Conversation" → "Coloring"

Qt: "Conversation" → "Coloring"

Change actionViewColorizeNewConversationRule to
actionViewColorizeNewColoringRule and change its text accordingly.
We're building a rule based on a general filter, not a conversation.

Change-Id: Ic408050eed6f24690e3e759e6963f9930fe4b5e9
Reviewed-on: https://code.wireshark.org/review/13266
Reviewed-by: Gerald Combs <gerald@wireshark.org>
Petri-Dish: Gerald Combs <gerald@wireshark.org>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Anders Broman <a.broman58@gmail.com>