Add the ability to create DigitalOcean Spaces

Description of your changes

Adds the ability to create the Space resource which is an s3 bucket on DigitalOcean.

Fixes https://github.com/crossplane-contrib/provider-digitalocean/issues/24

I have:

• [x] Read and followed Crossplane's contribution process.
• [x] Run make reviewable test to ensure this PR is ready for review.

How has this code been tested

Ran locally using a kind cluster.

@kimschles or @hasheddan This is ready for review if either you have any time!