schema.json: string_matcher object not complete

[petski]

ShouldBeEmpty and ShouldNotBeEmpty are not present in https://smocker.dev/smocker.schema.json

See https://github.com/smocker-dev/smocker/blob/main/server/types/matchers.go#L21 for a complete list of string_matchers.

--- /tmp/inschema	2024-07-25 14:26:53.690076590 +0200
+++ /tmp/incode	2024-07-25 14:25:50.711300857 +0200
@@ -5,6 +5,7 @@
 "ShouldEqual"
 "ShouldEqualJSON"
 "ShouldStartWith"
+"ShouldBeEmpty"
 "ShouldMatch"
 "ShouldNotResemble"
 "ShouldNotAlmostEqual"
@@ -12,4 +13,5 @@
 "ShouldNotEndWith"
 "ShouldNotEqual"
 "ShouldNotStartWith"
+"ShouldNotBeEmpty"
 "ShouldNotMatch"