feat: Introduce v1beta1 API for experimental channel

[shorim]

Description

Changes proposed in this pull request (what was done and why):

• Create a v1beta1 version for LogPipeline, TracePipeline and MetricPipeline. Currently, they are just clones of the CRDs in the v1alpha1 version.
• The kubebuilder marker +kubebuilder:storageversion is explicitly set for the types in the v1beta1 package. Therefore, when the CRDs are auto-generated for the development variant, the v1beta1 version is set as the stored version
• Adjust the existing manifests target to auot-generate only the CRDs for the v1alpha1 version
• Create a new target called manifests-dev which auto-generates the CRDs for both v1alpha1 and v1beta1 versions for the development release
• Use manifests-dev target as a dependency in deploy-dev target
• Rename otlp in the names of fields, types and functions to OTLP

Changes refer to particular issues, PRs or documents:
#848

Traceability

• The PR is linked to a GitHub issue.
• New features have a milestone set.
• New features have defined acceptance criteria in a corresponding GitHub Issue, and all criteria are satisfied with this PR.
• The corresponding GitHub issue has a respective area and kind label.
• The follow-up issues (if any) are linked in the Related Issues section.
• Adjusted the documentation if the change is user-facing.
• The feature is unit-tested
• The feature is e2e-tested