Rename tlstore to store (#1507)

This PR renames the `@tldraw/tlstore` package to `@tldraw/store`, mainly
to avoid confusion between `TLStore`. Will be doing the same with other
packages.

### Change Type

- [x] `major` — Breaking Change

### Release Notes

- Replace @tldraw/tlstore with @tldraw/store

packages/store/src/lib/BaseRecord.ts

@@ -0,0 +1,24 @@
+/** @public */
+export type ID<R extends UnknownRecord> = string & { __type__: R }
+
+/** @public */
+export type IdOf<R extends UnknownRecord> = R['id']
+
+/**
+ * The base record that all records must extend.
+ *
+ * @public
+ */
+export interface BaseRecord<TypeName extends string, Id extends ID<UnknownRecord>> {
+	readonly id: Id
+	readonly typeName: TypeName
+}
+
+/** @public */
+export type UnknownRecord = BaseRecord<string, ID<UnknownRecord>>
+
+export type OmitMeta<R extends UnknownRecord> = R extends R ? Omit<R, 'id' | 'typeName'> : R
+
+export function isRecord(record: unknown): record is UnknownRecord {
+	return typeof record === 'object' && record !== null && 'id' in record && 'typeName' in record
+}