change share and snapshot endpoints to by id and not by name. Fixes #…

[schakrava]

…1807

ids don't change during the lifecycle of the resource and let's us rename
shares easily.

[phillxnet]

@schakrava On a quick look at these changes I think we will have the same issue as we had earlier with the API change for pools (re:scrubs) where smart_manager_taskdefinition contains (within field json_meta) now defunct references ie "share": "luks-share" for snapshot tasks. This will presumably self correct for all new tasks (as with pool scrub tasks) but we are then left with no snapshot task json_meta name reference and will have to resolve to a name (might be tricky in places). Otherwise task tables will display the id rather than the name.

Requesting that this be debugged and fixed prior to the next stable release.

For pools I stamped the current name within the json_meta (not ideal but allowed for a work around with existing task mechanisms with only cosmetic artefacts there after) ie see:
pr #1760 "fix scheduled scrub regression re pool api changes. Fixes #1759"