feat: refactor api spec to use OpenAPI and add missing spec

Convert the existing swagger2.0 file to a moden OpenAPI file.
Add missing endpoitns and model definitions.

Signed-off-by: Lucas Roesler <roesler.lucas@gmail.com>

gateway/vendor/github.com/go-ozzo/ozzo-validation/v4/string.go

@@ -0,0 +1,64 @@
+// Copyright 2016 Qiang Xue. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package validation
+
+type stringValidator func(string) bool
+
+// StringRule is a rule that checks a string variable using a specified stringValidator.
+type StringRule struct {
+	validate stringValidator
+	err      Error
+}
+
+// NewStringRule creates a new validation rule using a function that takes a string value and returns a bool.
+// The rule returned will use the function to check if a given string or byte slice is valid or not.
+// An empty value is considered to be valid. Please use the Required rule to make sure a value is not empty.
+func NewStringRule(validator stringValidator, message string) StringRule {
+	return StringRule{
+		validate: validator,
+		err:      NewError("", message),
+	}
+}
+
+// NewStringRuleWithError creates a new validation rule using a function that takes a string value and returns a bool.
+// The rule returned will use the function to check if a given string or byte slice is valid or not.
+// An empty value is considered to be valid. Please use the Required rule to make sure a value is not empty.
+func NewStringRuleWithError(validator stringValidator, err Error) StringRule {
+	return StringRule{
+		validate: validator,
+		err:      err,
+	}
+}
+
+// Error sets the error message for the rule.
+func (r StringRule) Error(message string) StringRule {
+	r.err = r.err.SetMessage(message)
+	return r
+}
+
+// ErrorObject sets the error struct for the rule.
+func (r StringRule) ErrorObject(err Error) StringRule {
+	r.err = err
+	return r
+}
+
+// Validate checks if the given value is valid or not.
+func (r StringRule) Validate(value interface{}) error {
+	value, isNil := Indirect(value)
+	if isNil || IsEmpty(value) {
+		return nil
+	}
+
+	str, err := EnsureString(value)
+	if err != nil {
+		return err
+	}
+
+	if r.validate(str) {
+		return nil
+	}
+
+	return r.err
+}