feat(opnsense-config): Add MaybeString type to preserve xml serialization of empty elements

harmony-rs/Cargo.lock

@@ -440,6 +440,12 @@ dependencies = [
  "cipher",
 ]
 
+[[package]]
+name = "diff"
+version = "0.1.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "56254986775e3233ffa9c4d7d3faaf6d36a2c09d30b20687e9f88bc8bafc16c8"
+
 [[package]]
 name = "digest"
 version = "0.10.7"
@@ -1242,6 +1248,7 @@ dependencies = [
  "async-trait",
  "env_logger",
  "log",
+ "pretty_assertions",
  "russh",
  "russh-keys",
  "serde",
@@ -1426,6 +1433,16 @@ dependencies = [
  "zerocopy",
 ]
 
+[[package]]
+name = "pretty_assertions"
+version = "1.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3ae130e2f271fbc2ac3a40fb1d07180839cdbbe443c7a27e1e3c13c5cac0116d"
+dependencies = [
+ "diff",
+ "yansi",
+]
+
 [[package]]
 name = "primeorder"
 version = "0.13.6"
@@ -2594,6 +2611,12 @@ dependencies = [
  "tracing",
 ]
 
+[[package]]
+name = "yansi"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cfe53a6657fd280eaa890a3bc59152892ffa3e30101319d168b781ed6529b049"
+
 [[package]]
 name = "yaserde"
 version = "0.11.1"