/api/projects does not support pagination

[kiyoto]

Without pagination (or filter, or something...) it's not possible to retrieve the list of all projects. When Digdag is set up to create many projects automatically (say, in the case of Treasure Data), it becomes difficult to get the full list of projects.

c.f.

digdag/digdag-server/src/main/java/io/digdag/server/rs/ProjectResource.java

Line 264 in eb44c91

collection = ps.getProjects(100, Optional.absent())

[yoyama]

@kiyoto Thank you for your proposal and sorry for late reply.
I agree with requirement of pagination. But I don't know there are something reasons for it or not.
So I will discuss with @muga and make decision to accept this requet or not.

[yoyama]

The PR #1697 has supported it.