feat: removing deprecated fields

[devotional-phoenix-97]

Feature Request

Describe the Feature Request

We have deprecated some fields which we should remove as part of v1alpha3

Describe Preferred Solution

• requestor: Change to annotation
• managedByPaas: Change to annotation
• managed_by_suffix: part of go template

Additional Context

Part of v1alpha3 feature

If the feature request is approved, would you be willing to submit a PR?

• Yes
• No

[devotional-phoenix-97]

Initial work done by PR #639