Filter collectors on MessagesWidget

[erikn69]

• This PR adds a second filter group to MessageCollector, MessageCollector could aggreate other MessagesAggregateInterface, With this PR it is easier to filter messages from a certain collector(#1560)
• Another problem that is solved is if there is only one label/collector, it is not necessary to add the filter, because it removes/displays all the messages
• In case there are unlabeled messages, the NONE filter is added, which allows them to be filtered; previously it was not possible to filter this type of messages
• There was a CSS problem, the bottom only took into account the search bar, but not the filters, sometimes the filters obstruct the view of the message, I did increase enough padding to display correctly