OPT-793 I can see a preview of the flow node filter

• 
• Done

OPT-795 Add endpoint to map element ids to element names

• 
• Done

OPT-796 Flow Node filter displays flow node names instead of ids

• 
• Done

OPT-794 Make Flow Node filter modal bigger

• 
• Done

OPT-797 Disable "Create Filter" button if Flow Node filter is not valid

• 
• Done