Detailed explanation of different paths through states

[SebastianOpriel]

It would be great to have example explanation which paths through states are to be expected and in which cases those transitions could happen. https://github.com/International-Data-Spaces-Association/ids-specification/blob/71bc11c641a34685a72ab8e1d5eb9a8e298869df/negotiation/contract.negotiation.protocol.md?plain=1#L33C6-L33C6

[SebastianOpriel]

e.g. following transitions might make no sense:

• init -> offered -> requested
• init -> requested -> agreed

[sebbader-sap]

Proposal: Add a matrix to the linked file to map states explicitly to allowed messages:

• non-normative
• Columns: Start State | End State | Message/Transition | Actor | Comment/Example

[SebastianOpriel]

Provided a suggestion

• Provide non-normative examples of state transitions and adjust state description #138
• Pull abbreviated messages as transition triggers into edges of "contract negotiation state machine" #137