Scheduled reports: Download, a report for a period as a ZIP

inbuxa:ReportExport/set creates {reportId, from?, to?}: the report built
for that period (its last full one by default, at most 90 days back, as
far as metrics are kept) as a ZIP of summary.txt and the section CSVs,
stored as an upload, mailing nobody. Reading needs sysScheduledReportGet,
as seeing the report does; a tenant administrator downloads only their
own; every download is in the audit log. A download doesn't move the
deliverability baseline the next mail compares with.

crates/jmap-proto/src/request/parser.rs

@@ -743,6 +743,20 @@ impl<'de> Visitor<'de> for CallVisitor {
                     return Err(de::Error::invalid_length(1, &self));
                 }
             },
+            (MethodFunction::Get, MethodObject::ReportExport) => match seq.next_element() {
+                Ok(Some(value)) => RequestMethod::Get(GetRequestMethod::ReportExport(value)),
+                Err(err) => RequestMethod::invalid(err),
+                Ok(None) => {
+                    return Err(de::Error::invalid_length(1, &self));
+                }
+            },
+            (MethodFunction::Set, MethodObject::ReportExport) => match seq.next_element() {
+                Ok(Some(value)) => RequestMethod::Set(SetRequestMethod::ReportExport(value)),
+                Err(err) => RequestMethod::invalid(err),
+                Ok(None) => {
+                    return Err(de::Error::invalid_length(1, &self));
+                }
+            },
             // inbuxa: journaling
             (MethodFunction::Get, MethodObject::JournalEntry) => match seq.next_element() {
                 Ok(Some(value)) => RequestMethod::Get(GetRequestMethod::JournalEntry(value)),