SCIM: users, groups, queries, PATCH, Bulk and cursors at /scim/v2, over x:Account (SCIM-1 to SCIM-57)

Every SCIM operation becomes the x:Account get, query or set JMAP makes,
as the service principal, so permissions, tenant scope and limits,
address uniqueness and account destruction are enforced in one place.
Discovery is anonymous; everything else takes an API key as a bearer
token and nothing else. Domains open to SCIM carry a flag in the domain
cache. Filters take eq and and, answered from the account indexes, with
unindexed attributes checked on at most 200 candidates. Cursors are
stateless, HMAC-sealed under the server key. PATCH applies to the
resource in memory and saves it as a PUT, so it is all or nothing.
Groups get an address from their display name on the principal's
domain; membership is written on each user.

Every write emits one of five new scim.* events (ids 637 to 641), also
added to the packaged schema. The helpers the surviving SCIM suites
import are rebuilt from the spec; scim_tests runs the new acceptance
suite and the surviving tenant isolation suite, and both pass.

crates/common/src/cache/principals.rs

@@ -158,7 +158,11 @@ impl Server {
                 if domain.allow_relaying {
                     flags |= DOMAIN_FLAG_RELAY;
                 }
-
+                // inbuxa: SCIM-15, SCIM-58: the domain is open to SCIM, and SCIM is
+                // authoritative for its accounts
+                if domain.allow_scim_provisioning {
+                    flags |= crate::auth::DOMAIN_FLAG_SCIM;
+                }
 
                 let sub_addressing_custom = match domain.sub_addressing {
                     SubAddressing::Enabled => {