validation: handler/filter for lambda routes + remove MvcValidator

- Remove `MvcValidator`. Merge content into `BeanValidator`
- Rename BeanValidator.validate to BeanValidator.apply (avoid method name conflict)
- Creates BeanValidator.validate() route handler/filter which intercept calls to HTTP request object and run validator
- TODO: if we agreed on merging of MvcValidator we can remove/get rid of `jooby-validation` module

Author: jknack

docs/asciidoc/modules/avaje-validator.adoc

@@ -64,7 +64,7 @@ import io.jooby.avaje.validator.AvajeValidatorModule;
 import io.jooby.avaje.validator.AvajeValidatorModule
 
 {
-  install(new AvajeValidatorModule())
+  install(AvajeValidatorModule())
 }
 ----
 
@@ -139,17 +139,15 @@ class Controller {
 
 4) Usage in in script/lambda routes
 
-Jooby doesn't provide fully native bean validation in script/lambda at the moment,
-but you can use a helper that we utilize under the hood in MVC routes:
-
 .Java
 [source, java, role="primary"]
 ----
 import io.jooby.validation.BeanValidator;
 
 {
+  use(BeanValidator.validate());
   post("/validate", ctx -> {
-    Bean bean = BeanValidator.validate(ctx, ctx.body(Bean.class));
+    Bean bean = ctx.body(Bean.class);
     ...
   });
 }
@@ -161,15 +159,31 @@ import io.jooby.validation.BeanValidator;
 import io.jooby.validation.BeanValidator
 
 {
+  use(BeanValidator.validate())
   post("/validate") {
-    val bean = BeanValidator.validate(ctx, ctx.body(Bean.class))
+    val bean = ctx, ctx.body(Bean.class)
     ...
   }
 }
 ----
 
 `BeanValidator.validate()` behaves identically to validation in MVC routes.
-It also supports validating list, array, and map of beans
+It also supports validating list, array, and map of beans.
+
+There is a handler version of it, so you can apply per route:
+
+.validate
+[source, java]
+----
+import io.jooby.validation.BeanValidator.validate;
+
+{
+  post("/validate", validate(ctx -> {
+    Bean bean = ctx.body(Bean.class);
+    ...
+  }));
+}
+----
 
 === Constraint Violations Rendering
 

docs/asciidoc/modules/hibernate-validator.adoc

@@ -27,7 +27,7 @@ import io.jooby.hibernate.validator.HibernateValidatorModule;
 import io.jooby.hibernate.validator.HibernateValidatorModule
 
 {
-  install(new HibernateValidatorModule())
+  install(HibernateValidatorModule())
 }
 ----
 
@@ -102,17 +102,15 @@ class Controller {
 
 4) Usage in in script/lambda routes
 
-Jooby doesn't provide fully native bean validation in script/lambda at the moment,
-but you can use a helper that we utilize under the hood in MVC routes:
-
 .Java
 [source, java, role="primary"]
 ----
 import io.jooby.validation.BeanValidator;
 
 {
+  use(BeanValidator.validate());
   post("/validate", ctx -> {
-    Bean bean = BeanValidator.validate(ctx, ctx.body(Bean.class));
+    Bean bean = ctx.body(Bean.class);
     ...
   });
 }
@@ -124,8 +122,9 @@ import io.jooby.validation.BeanValidator;
 import io.jooby.validation.BeanValidator
 
 {
+  use(BeanValidator.validate())
   post("/validate") {
-    val bean = BeanValidator.validate(ctx, ctx.body(Bean.class))
+    val bean = ctx, ctx.body(Bean.class)
     ...
   }
 }
@@ -134,6 +133,21 @@ import io.jooby.validation.BeanValidator
 `BeanValidator.validate()` behaves identically to validation in MVC routes.
 It also supports validating list, array, and map of beans
 
+There is a handler version of it, so you can apply per route:
+
+.validate
+[source, java]
+----
+import io.jooby.validation.BeanValidator.validate;
+
+{
+  post("/validate", validate(ctx -> {
+    Bean bean = ctx.body(Bean.class);
+    ...
+  }));
+}
+----
+
 === Constraint Violations Rendering
 
 `HibernateValidatorModule` provides default built-in error handler that