Be agnostic to the use of % reference with Milestone strings
Milestones are denoted by the % prefix in Markdown. It's likely users would use this prefix intermittently when specifying milestones in GLQL.
This is more of a problem for milestones than # is for issues or & for epics, because the latter correspond to iids.
The use of % should be optional so that the following statements are equal:
milestone = "17.0"milestone = "%17.0"
Edited by John Hope