Request: spacelift_space datasource should support finding by name (not just slug)

[tthrone-atomic]

The spacelift_space data source should allow finding by the human readable name. It currently only supports finding by the slug.

An example use case

data "spacelift_space" "space" { name = "MySpace" }

resource "spacelift_policy" "policy" ... space_id = data.spacelift_space.space.id }