API: There are two endpoints to search for projects

In the current API, there are two possible ways of searching for projects:

• GET /projects?search=hello (added in 2015 by 8689ce1e)
• GET /projects/search/hello (added in 2013 by 4cfbfbb8)

I think the first endpoint is sufficient so we should probably schedule the removal of the latter for 9.0 or later (but at least schedule it).

/cc @DouweM @stanhu