Remove Web Mercator Reprojection and provide CRS in MAML mask

[Lknechtli]

Problem description

#4694 added support for supplying a MAML mask, but included the mask in Web Mercator because that is what MAML expects (must match output projection for MAML's use-case). That was a temporary workaround until MAML accepts a CRS so that it can handle reprojection for masking purposes.

Ideally, we should supply the coordinates in lat/lng since that follows the GeoJSON spec and while MAML isn't GeoJSON exactly, it is close enough that one would expect it to follow conventions there.

Replication Steps

Create an analysis with a mask using lat/lng coordinates. It will not mask correctly.

Expected Behavior or Output

When an AST is posted to the API using lat/lng coordinates in a mask node instead of the same projection as the underlying database representation, the mask node should still work correctly by including the CRS.