[RSR-1004] Add constraints to update compas flow bindings

[hkaroun]

Related to #351
User Story

1. As a process when I retrieved compas:Flow@ExtRefldinst @ExtRefprefix @ExtReflnClass @ExtReflnInst :

• Search in /Substation for LNodes with ExtRefldinst @ExtReflnClass @ExtReflnInst

• A single @iedname should be found by discriminating IEDs using one or more of the following attributes:

@FlowSourceIEDType = LNode/compas:ICDHeader @IEDType @FlowSourceIEDredundancy= LNode/compas:ICDHeader @IEDredundancy @FlowIEDSystemVersioninstance= LNode/compas:ICDHeader @IEDSystemVersioninstance For each attribute, if the value is not defined, disregard it as a criterion.

2. As a process when I found several LNode/iedname matching the criteria defined above :

• This is a blocking error and continue the process until the end of step (Error message : "Several LNode@IedName ('XXX', 'XXXX') are found in the bay 'XXX' for the following compas-flow attributes :
• @FlowSourceIEDType 'XXXX' @FlowSourceIEDredundancy 'XXXX' @FlowIEDSystemVersioninstance 'XXX'").

Acceptance criteria

• Check that an error is raised when the process obtains more than one @iedname