Implement a basic benchmark test, and deprecate derivation.map()/flatMap()

This starts a new workspace at `packages/benchmarks` where future benchmarks
are going to sit. For now, it only contains a basic profile of a `sequence.play()`
setup.

It also removes all uses of `AbstractDerivation.map()/flatMap()` and uses prisms
instead.

packages/benchmarks/devEnv/serveBenchmarks.ts

@@ -0,0 +1,29 @@
+import path from 'path'
+import {definedGlobals} from '../../../theatre/devEnv/definedGlobals'
+
+const benchmarksDir = path.join(__dirname, '..')
+
+const port = 8087
+
+const allEnvs = {
+  '0.5.0': () => {},
+}
+
+require('esbuild')
+  .serve(
+    {
+      port,
+      servedir: path.join(benchmarksDir, 'src'),
+    },
+    {
+      entryPoints: [path.join(benchmarksDir, 'src/index.tsx')],
+      target: ['firefox88'],
+      loader: {'.png': 'file', '.glb': 'file', '.svg': 'dataurl'},
+      bundle: true,
+      sourcemap: true,
+      define: definedGlobals,
+    },
+  )
+  .then((server: unknown) => {
+    console.log('serving', 'http://localhost:' + port)
+  })