chore: add crdAnnotation to datadog-crds chart

[v-starodubov]

What this PR does / why we need it:

Adds a crdAnnotations value to the datadog-crds chart that allows users to specify arbitrary annotations on all CRD resources. This is particularly useful for ArgoCD users who need annotations such as argocd.argoproj.io/sync-options: SkipDryRunOnMissingResource=true to prevent sync errors when CRDs are not yet established in the cluster.

All 9 CRD templates have been updated to render crdAnnotations, and update-crds.sh has been updated to inject the block automatically on future CRD refreshes.

Example usage:

crdAnnotations:
  argocd.argoproj.io/sync-options: SkipDryRunOnMissingResource=true

Which issue this PR fixes

(optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged)

• fixes [BUG] CRDs too big for ArgoCD, adding annotation to CRDs would be an easy fix #2341

Special notes for your reviewer:

• crdAnnotations defaults to {} and is a no-op when not set — no changes to existing rendered output.
• keepCrds behavior is unchanged; crdAnnotations is additive alongside it.
• update-crds.sh sed injection updated so the block is preserved on future upstream CRD refreshes.

Checklist

[Place an '[x]' (no spaces) in all applicable fields. Please remove unrelated fields.]

• All commits are signed (see: signing commits)
• Chart Version semver bump label has been added (use <chartName>/minor-version, <chartName>/patch-version, or <chartName>/no-version-bump)
• For datadog or datadog-operator chart or value changes, update the test baselines (run: make update-test-baselines)

GitHub CI takes care of the below, but are still required:

• Documentation has been updated with helm-docs (run: .github/helm-docs.sh)
• CHANGELOG.md has been updated
• Variables are documented in the README.md