Node Annotations and Command-Line Flags Should Work Cohesively

[aauren]

Is your feature request related to a problem? Please describe. Node annotations and command-line flags for BGP peers do not currently work together. Instead they end up being mutually exclusive. If kube-router detects that you have configured peers via command-line flags, it doesn't even attempt to read information from node annotations. This can be confusing for users that may want leverage both methods of configuration for different purposes.

Describe the solution you'd like Where possible, node annotations and command-line parameters should work together cohesively

[aauren]

Relates to #1371