Realign search buttons

The search buttons should be realigned to fit into the other UI elements, eg:

• size small
• align horizontally (instead of vertically)

assigned to @marc.hanisch

added Frontend UI/UX labels

changed the description

added Ready4Process label

added Improvement label

added In Progress label and removed Ready4Process label

mentioned in merge request !178 (merged)

added Testing label and removed In Progress label

closed with merge request !178 (merged)

mentioned in commit 1a81aada