feat: decryption plugin (#430)

* feat: Implemented decryption plugin

* fix: Removed interface test file

* fix: Test case

* fix: Test case for plugin

* fix: test case change

* fix: resolved pr comments

* fix: resolved pr comments

* fix: removed mock dcrypter

* fix: formatting

* fix: removed config, close function, enhanced test cases

* fix: test cases enhancement, formatting

pkg/plugin/definition/decrypter.go

@@ -0,0 +1,15 @@
+package definition
+
+import "context"
+
+// Decrypter defines the methods for decryption.
+type Decrypter interface {
+	// Decrypt decrypts the given body using the provided privateKeyBase64 and publicKeyBase64.
+	Decrypt(ctx context.Context, encryptedData string, privateKeyBase64, publicKeyBase64 string) (string, error)
+}
+
+// DecrypterProvider initializes a new decrypter instance with the given config.
+type DecrypterProvider interface {
+	// New creates a new decrypter instance based on the provided config.
+	New(ctx context.Context, config map[string]string) (Decrypter, func() error, error)
+}