Add endpoint: Make it possible to retrieve replacement terms for obsoleted ones

[anitacaron]

From https://github.com/mapping-commons/ols-mapping-commons/issues/5

• [ ] Depends on Add replaced by property to standard mapping properties sssom-py#263

[matentzn]

I think we still want that, but in a future iteration of the API.

[anitacaron]

Can you give more details?

[matentzn]

Dont worry, leave it closed now, we will re-open when it becomes important.

[anitacaron]

Ok, I need help understanding the title of the issue.

[matentzn]

I changed the name so you get a sense.