Add cache and artifacts paths to HardhatConfig

Author: schaable

v-next/core/src/types/config.ts

@@ -52,4 +52,12 @@ export interface HardhatUserConfig {}
  * The resolved Hardhat configuration.
  */
 // eslint-disable-next-line @typescript-eslint/no-empty-interface -- Used through module aumentation
-export interface HardhatConfig {}
+export interface HardhatConfig {
+  paths: ProjectPathsConfig;
+}
+
+export interface ProjectPathsConfig {
+  root: string;
+  cache: string;
+  artifacts: string;
+}