feat: add request-validation plugin (#700)

Signed-off-by: sjcsjc123 <1401189096@qq.com>

plugins/wasm-go/extensions/request-validation/README.md

@@ -0,0 +1,146 @@
+# 功能说明
+`request-validation`插件用于提前验证向上游服务转发的请求。该插件使用`JSON Schema`机制进行数据验证，可以验证请求的body及header数据。
+
+# 配置字段
+
+| 名称 | 数据类型 | 填写要求 | 默认值 | 描述 |
+| -------- | -------- | -------- |-----| -------- |
+|header_schema|object|选填| -   |配置用于验证请求header的JSON Schema|
+|body_schema|object|选填| -   |配置用于验证请求body的JSON Schema|
+|rejected_code|number|选填| 403 |配置请求被拒绝时返回的HTTP状态码|
+|rejected_msg|string|选填| - |配置请求被拒绝时返回的HTTP应答Body|
+|enable_swagger|bool|选填| false |配置是否开启swagger文档验证|
+|enable_oas3|bool|选填| false |配置是否开启OAS3文档验证|
+
+**校验规则对header和body是一样的，下面以body为例说明**
+
+# 配置示例
+
+## 枚举（Enum）验证
+```yaml
+body_schema:
+  type: object
+  required:
+    - enum_payload
+  properties:
+    enum_payload:
+      type: string
+      enum:
+        - "enum_string_1"
+        - "enum_string_2"
+      default: "enum_string_1"
+```
+
+## 布尔（Boolean）验证
+```yaml
+body_schema:
+  type: object
+  required:
+    - boolean_payload
+  properties:
+    boolean_payload:
+      type: boolean
+      default: true
+```
+
+## 数字范围（Number or Integer）验证
+```yaml
+body_schema:
+  type: object
+  required:
+    - integer_payload
+  properties:
+    integer_payload:
+      type: integer
+      minimum: 1
+      maximum: 10
+```
+
+## 字符串长度（String）验证
+```yaml
+body_schema:
+  type: object
+  required:
+    - string_payload
+  properties:
+    string_payload:
+      type: string
+      minLength: 1
+      maxLength: 10
+```
+
+## 正则表达式（Regex）验证
+```yaml
+body_schema:
+  type: object
+  required:
+    - regex_payload
+  properties:
+    regex_payload:
+      type: string
+      minLength: 1
+      maxLength: 10
+      pattern: "^[a-zA-Z0-9_]+$"
+```
+
+## 数组（Array）验证
+```yaml
+body_schema:
+  type: object
+  required:
+    - array_payload
+  properties:
+    array_payload:
+      type: array
+      minItems: 1
+      items:
+        type: integer
+        minimum: 1
+        maximum: 10
+      uniqueItems: true
+      default: [1, 2, 3]
+```
+
+## 多字段组合（Combined）验证
+```yaml
+body_schema:
+  type: object
+  required:
+    - boolean_payload
+    - array_payload
+    - regex_payload
+  properties:
+    boolean_payload:
+      type: boolean
+    array_payload:
+      type: array
+      minItems: 1
+      items:
+          type: integer
+          minimum: 1
+          maximum: 10
+      uniqueItems: true
+      default: [1, 2, 3]
+    regex_payload:
+      type: string
+      minLength: 1
+      maxLength: 10
+      pattern: "^[a-zA-Z0-9_]+$"
+```
+
+## 自定义拒绝信息
+```yaml
+body_schema:
+  type: object
+  required:
+    - boolean_payload
+  properties:
+    boolean_payload:
+      type: boolean
+rejected_code: 403
+rejected_msg: "请求被拒绝"
+```
+
+# 本地调试
+
+参考[使用 GO 语言开发 WASM 插件](https://higress.io/zh-cn/docs/user/wasm-go#%E4%B8%89%E6%9C%AC%E5%9C%B0%E8%B0%83%E8%AF%95)