update to prost 0.12

[Fabian-Gruenbichler]

derived Enumerations now provide their own conversion implementation from i32, so map any DecodeErrors originating from there to InvalidEncoding, and drop the manual impls that existed before.

Closes: #153

[Fabian-Gruenbichler]

note that I have no deeper knowledge of parsec or prost, but this is currently blocking some upgrades in Debian, so I lent a hand ;)

[Fabian-Gruenbichler]

the build check fails because of unnecessary qualifications, see #151 (although that might bump MSRV too aggressively for your taste ;))

the MSRV check fails because the new prost requires a newer rustc - not sure what your policies are, so I'll leave that up to you!

[gowthamsk-arm]

Thanks for the changes. The PR looks good, just waiting for #151 to be resolved so that the CI tests can be completed.

[nc7s]

Meanwhile, prost has went to 0.13. Here's a "delta" patch for this PR:

--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,3 +14,3 @@
 [build-dependencies]
-prost-build = { version = "0.12.0", optional = true }
+prost-build = { version = "0.13.0", optional = true }
 
@@ -23 +23 @@
-prost = "0.12.0"
+prost = "0.13.0"
--- a/src/requests/response_status.rs
+++ b/src/requests/response_status.rs
@@ -297,2 +297,12 @@

+impl From<::prost::UnknownEnumValue> for ResponseStatus {
+    fn from(err: ::prost::UnknownEnumValue) -> Self {
+        warn!(
+            "Conversion from {} to ResponseStatus::InvalidEncoding.",
+            err
+        );
+        ResponseStatus::InvalidEncoding
+    }
+}
+
 impl From<::prost::DecodeError> for ResponseStatus {
--- a/src/operations_protobuf/generated_ops/mod.rs
+++ b/src/operations_protobuf/generated_ops/mod.rs
@@ -319,3 +319,3 @@
     assert_eq!(
-        <::prost::DecodeError as Into<ResponseStatus>>::into(Cipher::try_from(56).unwrap_err()),
+        <::prost::UnknownEnumValue as Into<ResponseStatus>>::into(Cipher::try_from(56).unwrap_err()),
         ResponseStatus::InvalidEncoding
@@ -323,3 +323,3 @@
     assert_eq!(
-        <::prost::DecodeError as Into<ResponseStatus>>::into(Cipher::try_from(-5).unwrap_err()),
+        <::prost::UnknownEnumValue as Into<ResponseStatus>>::into(Cipher::try_from(-5).unwrap_err()),
         ResponseStatus::InvalidEncoding
@@ -327,3 +327,3 @@
     assert_eq!(
-        <::prost::DecodeError as Into<ResponseStatus>>::into(Hash::try_from(89).unwrap_err()),
+        <::prost::UnknownEnumValue as Into<ResponseStatus>>::into(Hash::try_from(89).unwrap_err()),
         ResponseStatus::InvalidEncoding
@@ -331,3 +331,3 @@
     assert_eq!(
-        <::prost::DecodeError as Into<ResponseStatus>>::into(Hash::try_from(-4).unwrap_err()),
+        <::prost::UnknownEnumValue as Into<ResponseStatus>>::into(Hash::try_from(-4).unwrap_err()),
         ResponseStatus::InvalidEncoding
@@ -335,3 +335,3 @@
     assert_eq!(
-        <::prost::DecodeError as Into<ResponseStatus>>::into(EccFamily::try_from(78).unwrap_err()),
+        <::prost::UnknownEnumValue as Into<ResponseStatus>>::into(EccFamily::try_from(78).unwrap_err()),
         ResponseStatus::InvalidEncoding