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/DuckDBDecimalValue.ts

@@ -0,0 +1,38 @@
+import {
+  DuckDBDecimalFormatOptions,
+  stringFromDecimal,
+} from './conversion/stringFromDecimal.js';
+import { Json } from './Json.js';
+import { SpecialDuckDBValue } from './SpecialDuckDBValue.js';
+
+export class DuckDBDecimalValue extends SpecialDuckDBValue {
+  public readonly scaledValue: bigint;
+
+  public readonly scale: number;
+
+  constructor(scaledValue: bigint, scale: number) {
+    super();
+    this.scaledValue = scaledValue;
+    this.scale = scale;
+  }
+
+  public toDuckDBString(): string {
+    return stringFromDecimal(this.scaledValue, this.scale);
+  }
+
+  /** Returns a string representation appropriate to the host environment's current locale. */
+
+  public toLocaleString(
+    locales?: string | string[],
+    options?: DuckDBDecimalFormatOptions,
+  ): string {
+    return stringFromDecimal(this.scaledValue, this.scale, {
+      locales,
+      options,
+    });
+  }
+
+  public toJson(): Json {
+    return this.toDuckDBString();
+  }
+}