SMCP: Move wasmExtensions out of techPreview

In 2.1 WASM extensions support it's going to be GA, so:

• Wasm Extensions will be enabled by default
• We will keep the ability to disable it via spec.techPreview.wasmExtensions.enabled however this is not going to be documented
  • This is to provide an "escape hatch" if (unlikely) something goes wrong

We need to:

• Modify operator to enable WASM by default
• Change the docs accordingly removing the mentions to having to enabling it; assume it's enabled by default
• Change test suite (maistra-test-tool repository) accordingly.

AC:

There's no need to set spec.techPreview.wasmExtensions.enabled to true anymore. In fact, spec.techPreview.wasmExtensions should be hidden from docs and any user visible artifact, like the SMCP templates.

WASM support should be enabled by default. (Unless spec.techPreview.wasmExtensions.enabled is explicitly set to false. Again, this ability is hidden from the user)

There should be a deployment "wasm-cacher-basic" in the control plane namespace.