MM-22785 audit server CLI (#14144)

Add auditing to server CLI.

Also:
- simplify auditing in API layer
- reduce number of AddMeta calls
- have models serialize themselves
- more consistent field naming

go.mod

@@ -18,6 +18,7 @@ require (
 	github.com/dyatlov/go-opengraph v0.0.0-20180429202543-816b6608b3c8
 	github.com/fatih/color v1.9.0 // indirect
 	github.com/fortytw2/leaktest v1.3.0 // indirect
+	github.com/francoispqt/gojay v1.2.13
 	github.com/fsnotify/fsnotify v1.4.7
 	github.com/go-gorp/gorp v2.0.0+incompatible // indirect
 	github.com/go-sql-driver/mysql v1.5.0
@@ -43,7 +44,7 @@ require (
 	github.com/icrowley/fake v0.0.0-20180203215853-4178557ae428
 	github.com/jaytaylor/html2text v0.0.0-20190408195923-01ec452cbe43
 	github.com/jmoiron/sqlx v1.2.0
-	github.com/jonboulle/clockwork v0.1.0
+	github.com/jonboulle/clockwork v0.1.0 // indirect
 	github.com/konsorten/go-windows-terminal-sequences v1.0.2 // indirect
 	github.com/lib/pq v1.3.0
 	github.com/magiconair/properties v1.8.1 // indirect
@@ -69,9 +70,9 @@ require (
 	github.com/pelletier/go-toml v1.6.0 // indirect
 	github.com/pkg/errors v0.9.1
 	github.com/prometheus/client_golang v1.4.0
-	github.com/prometheus/client_model v0.2.0
+	github.com/prometheus/client_model v0.2.0 // indirect
 	github.com/rs/cors v1.7.0
-	github.com/russellhaering/goxmldsig v0.0.0-20180430223755-7acd5e4a6ef7
+	github.com/russellhaering/goxmldsig v0.0.0-20180430223755-7acd5e4a6ef7 // indirect
 	github.com/rwcarlsen/goexif v0.0.0-20190401172101-9e8deecbddbd
 	github.com/segmentio/analytics-go v3.1.0+incompatible
 	github.com/segmentio/backo-go v0.0.0-20160424052352-204274ad699c // indirect