Remove Violations message

**This is a breaking change.**

Closes #96.

docs/custom-constraints.md

@@ -19,7 +19,7 @@ The `Constraint` message is used to define validation rules for messages or
 fields in a message. The constraints are then evaluated using
 the `protovalidate` tool to ensure that the data conforms to the specified
 rules. If any violations occur during validation, they are reported using
-the `Violations` message. The `Violation` message provides detailed information
+the `Violation` message. The `Violation` message provides detailed information
 about the violated constraint, including the field path, the constraint ID, and
 the error message.
 

docs/errors.md

@@ -9,16 +9,14 @@ three fields:
 - `constraint_id`: the id of the constraint that failed validation.
 - `message`: a human-readable error message for this violation.
 
-### Violations
+### Violation
 
-The `Violations` message is used to collect all violations that occur during
-constraint validation. It has one field:
+The `Violation` message is used to collect all violations that occur during
+constraint validation. One or more `Violation` messages are returned by
+`protovalidate` when a message fails to fulfill the requirements of the
+constraint validation.
 
-- `violations`: a repeated field of `Violation` messages. `Violations` are
-  returned by `protovalidate` when a message fails to fulfill the requirements
-  of the constraint validation.
-
-In summary, the `Constraints` and `Violations` messages provide a way to define
+In summary, the `Constraints` and `Violation` messages provide a way to define
 and enforce validation constraints using the Common Expression Language (CEL)
 syntax. Standard constraints are defined using the `Constraints` message and
 provide a set of predefined validation rules that can be applied to various.

proto/protovalidate-testing/buf/validate/conformance/harness/harness.proto

@@ -34,13 +34,19 @@ message TestConformanceResponse {
   map<string, TestResult> results = 1;
 }
 
+// ValidationError is the result if the test failed due to validation errors.
+message ValidationError {
+  // `violations` is a repeated field that contains all the `Violation` messages corresponding to the violations detected.
+  repeated Violation violations = 1;
+}
+
 // TestResult is the result of a single test. Only one of the fields will be set.
 message TestResult {
   oneof result {
     // success is true if the test succeeded.
     bool success = 1;
     // validation_error is the error if the test failed due to validation errors.
-    Violations validation_error = 2;
+    ValidationError validation_error = 2;
     // compilation_error is the error if the test failed due to compilation errors.
     string compilation_error = 3;
     // runtime_error is the error if the test failed due to runtime errors.

proto/protovalidate/buf/validate/validate.proto

@@ -4749,14 +4749,6 @@ message TimestampRules {
   extensions 1000 to max;
 }
 
-// `Violations` is a collection of `Violation` messages. This message type is returned by
-// protovalidate when a proto message fails to meet the requirements set by the `Constraint` validation rules.
-// Each individual violation is represented by a `Violation` message.
-message Violations {
-  // `violations` is a repeated field that contains all the `Violation` messages corresponding to the violations detected.
-  repeated Violation violations = 1;
-}
-
 // `Violation` represents a single instance where a validation rule, expressed
 // as a `Constraint`, was not met. It provides information about the field that
 // caused the violation, the specific constraint that wasn't fulfilled, and a