Complete redo of content indexing and querying (#517)

Complete redo of data store
Introduces live queries and live templates

common/syscalls/language.ts

@@ -0,0 +1,20 @@
+import { SysCallMapping } from "../../plugos/system.ts";
+import { parse } from "../markdown_parser/parse_tree.ts";
+import type { ParseTree } from "$sb/lib/tree.ts";
+import { languageFor } from "../languages.ts";
+
+export function languageSyscalls(): SysCallMapping {
+  return {
+    "language.parseLanguage": (
+      _ctx,
+      language: string,
+      code: string,
+    ): ParseTree => {
+      const lang = languageFor(language);
+      if (!lang) {
+        throw new Error(`Unknown language ${language}`);
+      }
+      return parse(lang, code);
+    },
+  };
+}