don't return the same route multiple times when shared to more then 2 spaces

[Benjamintf1]

Thanks for contributing to cloud_controller_ng. To speed up the process of reviewing your pull request please provide us with:

• A short explanation of the proposed change:

• similar to what's been done with service instances https://github.com/cloudfoundry/cloud_controller_ng/pull/3955, if a route is shared to more then two spaces, it will show up many times in the result

• still needs a test before it can be merged

• An explanation of the use cases your change solves if a route is shared to two spaces, it will show up

• Links to any other associated PRs

• [x] I have reviewed the contributing guide

• [ ] I have viewed, signed, and submitted the Contributor License Agreement

• [x] I have made this pull request to the main branch

• [ ] I have run all the unit tests using bundle exec rake

• [ ] I have run CF Acceptance Tests

[Benjamintf1]

i've tested this against a live environment and saw it does what i expect it to, need to add to the route unit tests to fix it.

[Benjamintf1]

wait, i thought it said 17 out of 17!?!?!