refactor previous commit a little, add fakejson module for simple parsing that doesn't use regex.

fakejson.ts

@@ -0,0 +1,26 @@
+export function getHex64(json: string, field: string): string {
+  let len = field.length + 3
+  let idx = json.indexOf(`"${field}":`) + len
+  let s = json.slice(idx).indexOf(`"`) + idx + 1
+  return json.slice(s, s + 64)
+}
+
+export function getInt(json: string, field: string): number {
+  let len = field.length
+  let idx = json.indexOf(`"${field}":`) + len + 3
+  let sliced = json.slice(idx)
+  let end = Math.min(sliced.indexOf(','), sliced.indexOf('}'))
+  return parseInt(sliced.slice(0, end), 10)
+}
+
+export function matchEventId(json: string, id: string): boolean {
+  return id === getHex64(json, 'id')
+}
+
+export function matchEventPubkey(json: string, pubkey: string): boolean {
+  return pubkey === getHex64(json, 'pubkey')
+}
+
+export function matchEventKind(json: string, kind: number): boolean {
+  return kind === getInt(json, 'kind')
+}