Use built-in DOMPurify types

Currently we have custom DOMPurify types (https://github.com/FlowCrypt/flowcrypt-browser/blob/b8aa4bebd85f33d2fd15b3682db5da8d4a74002b/extension/types/purify.d.ts), which are probably from some older version and can be outdated. DOMPurify provides built-in types for the actual version - https://github.com/cure53/DOMPurify/blob/main/dist/purify.cjs.d.ts, let's switch to using it.