TP: Provide the ability to create/update/delete a topology

[zrhoffman]

I'm submitting a ...

• new feature / enhancement request

Description

In Traffic Portal, users should have the ability to create a new or update/delete an existing topology.

Traffic Control components affected ...

• Traffic Portal

Acceptance Criteria

• on topology create/update, name is required and can only contain a-zA-z0-9 and dash.
• on topology create/update, description is required.
• on topology create/update, at least one cache group is required.
• the ability to add or remove one or more cache groups from a topology is supported.
• adding the same cache group to a topology multiple times is prohibited.
• the ability to define the primary parent/child relationship between topology cache groups is supported with the following exceptions:
  • EDGE_LOC cache groups cannot have child cache groups.
  • ORG_LOC cache groups cannot have parent cache groups and must have at least one child cache group
  • MID_LOC cache groups must have at least one child cache group
• the ability to define the secondary parent/child relationship between one or more topology cache groups is supported within the following rules:
• secondary parent selection is limited to cache groups defined in the topology and limited to cache groups of type MID_LOC or ORG_LOC
• secondary parent selection cannot be the same value as primary parent
• secondary parent selection cannot be the same value as the cache group (no self-parenting)
• secondary parent selection must be limited to cache groups of type ORG_LOC or MID_LOC
• removing a cache group from a topology will remove that cache group plus all child cache groups.
• removing a cache group (and it's children) will remove any secondary parent references to the removed cache groups.
• the ability to view the servers for each cache group is supported.
• on topology update, notify the user of the number of delivery services currently using the topology and confirm the update.
• deleting a topology requires user input/confirmation.
• on topology delete, prevent the delete if the topology is used by one or more delivery services.

See the Flexible Topologies PR for specifics: #4537