add duckdb-ui-client & other ts pkgs (#10)

* add duckdb-ui-client & other ts pkgs

* workflow fixes

* fix working dir

* no sparse checkout; specify package.json path

* path to pnpm-lock.yaml

* add check & build test

* workflow step descriptions

* use comments & names

* one more naming tweak

ts/pkgs/duckdb-data-values/src/conversion/stringFromBlob.ts

@@ -0,0 +1,17 @@
+/** Matches BLOB-to-VARCHAR conversion behavior of DuckDB. */
+export function stringFromBlob(bytes: Uint8Array): string {
+  let result = '';
+  for (const byte of bytes) {
+    if (
+      byte <= 0x1f ||
+      byte === 0x22 /* single quote */ ||
+      byte === 0x27 /* double quote */ ||
+      byte >= 0x7f
+    ) {
+      result += `\\x${byte.toString(16).toUpperCase().padStart(2, '0')}`;
+    } else {
+      result += String.fromCharCode(byte);
+    }
+  }
+  return result;
+}