dev: add setup-dev-env* tasks and narrow multicluster setup

[hidalgopl]

Add three dev-environment entry points to taskfiles/dev.yml that mirror the existing task dev:setup-multicluster-dev-env ergonomic for non-multicluster work:

task dev:setup-dev-env
Brings up a single k3s cluster with the operator + a basic
Redpanda cluster pre-applied. Equivalent to running the
acceptance suite up to AfterSetup and stopping there.

task dev:setup-dev-env-with-nodepools
Same as above plus two NodePool CRDs (3 brokers total)
pointing at the basic cluster. The pool count is wired
through -acceptance-setup-nodepools=N so callers can
override.

task dev:setup-multicluster-dev-env (existing)
Now passes -groups dev-env so the multicluster suite
narrows to stretch-cluster-basics.feature (the only
feature tagged @dev-env). Avoids running the full
multicluster suite locally just to bring up a stretch
cluster.

The implementation reuses the existing harpoon SuiteBuilder by adding two affordances:

• SuiteBuilder.SkipFeatures() — RunT runs setup + AfterSetup
  • teardown but skips the feature execution phases. This is the "setup only" semantic dev-env tasks need.
• -acceptance-setup-only testutil flag + an AfterSetup hook in acceptance/main_test.go that applies clusters/basic/cluster.yaml (with NodePools when N > 0) against the freshly-stood-up cluster.

The shared operator install now scopes its --additional-cmd-flags through a small operatorCmdFlags helper that appends --enable-v2-nodepools=true only when
-acceptance-setup-nodepools > 0. NodePool CRDs are only applied in that mode, so the v2 controller is only needed there. The operator's production default for
--enable-v2-nodepools is left unchanged.

stretch-cluster-basics.feature gains the @dev-env tag (used by the new -groups filter) and turns on rpkDebugBundle in its RBAC fixture so the multicluster operator's bundle surface is exercised end-to-end during local testing.

No changes in the operator behavior, this is just to make dev setup easier for spawning dev envs quickly.