Additional allocations

[mason-rogers]

Huge thanks @snags141 for laying the foundation of this feature

Carrying on from his work, it has been improved by fixing a couple bugs/making bits more efficient

• The original PR did not pre-check node resource eligibility, so when using additional ports it was able to pick a node which did not have room for the server -> leading to an error
  • Now, we pull eligible nodes for the given location first before we check allocations (through an endpoint newly made for this purpose)
• A new endpoint was introduced in WISP to only pull available allocations, rather than fetching all of them and filtering out assigned ones - ultimately more efficient