`views update` only overwrites existing connections

[bderrly]

If I have a view:

$ humioctl views show bderrly
   VIEW   | REPOSITORY | QUERY PREFIX  
+---------+------------+--------------+
  bderrly | foo       | bderrly       

and I run humioctl views update bderrly --connection "bar=bderrly"

I see:

$ humioctl views show bderrly
   VIEW   | REPOSITORY | QUERY PREFIX  
+---------+------------+--------------+
  bderrly | bar   | bderrly       

Either the update action should be additive by default or there should be a flag to signal intent to add another connection, e.g. humioctl views update bderrly --add-connection "bar=bderrly".

Of course this opens up the question of how to handle removing a connection. This could be handled with a flag to signal intent to delete the connection, e.g. humioctl views update bderrly --del-connection "foo".