Moved certrbot plugin list to backend

frontend doesn't include when building in react version
adds swagger for existing dns-providers endpoint

backend/schema/paths/nginx/certificates/test-http/post.json

@@ -0,0 +1,46 @@
+{
+	"operationId": "testHttpReach",
+	"summary": "Test HTTP Reachability",
+	"tags": ["Certificates"],
+	"security": [
+		{
+			"BearerAuth": ["certificates"]
+		}
+	],
+	"requestBody": {
+		"description": "Test Payload",
+		"required": true,
+		"content": {
+			"application/json": {
+				"schema": {
+					"type": "object",
+					"additionalProperties": false,
+					"required": ["domains"],
+					"properties": {
+						"domains": {
+							"$ref": "../../../../common.json#/properties/domain_names"
+						}
+					}
+				}
+			}
+		}
+	},
+	"responses": {
+		"200": {
+			"description": "200 response",
+			"content": {
+				"application/json": {
+					"examples": {
+						"default": {
+							"value": {
+								"test.example.org": "ok",
+								"test.example.com": "other:Invalid domain or IP",
+								"nonexistent.example.com": "404"
+							}
+						}
+					}
+				}
+			}
+		}
+	}
+}