Remove CasperLabs references[CD-96]

[devendran-m]

This PR resolves;

1. Jira CD-96 - Remove obsolete CasperLabs references in legacy docs.
2. The changes that were regressed when updating the "monitoring-and-consuming-events" updates for 2.0.0. PR reference here

Following are the files where the changes are incorporated;

        modified:   docs/concepts/economics/index.md
        modified:   docs/concepts/glossary/index.md
        modified:   docs/concepts/serialization/primitives.md
        modified:   docs/concepts/serialization/structures.md
        modified:   docs/concepts/serialization/types.md
        modified:   docs/developers/cli/opcode-costs.md
        modified:   docs/operators/setup/install-node.md
        modified:   versioned_docs/version-2.0.0/concepts/accounts-and-keys.md
        modified:   versioned_docs/version-2.0.0/concepts/economics/index.md
        modified:   versioned_docs/version-2.0.0/concepts/glossary/index.md
        modified:   versioned_docs/version-2.0.0/concepts/serialization/structures.md
        modified:   versioned_docs/version-2.0.0/concepts/serialization/types.md
        modified:   versioned_docs/version-2.0.0/disclaimer.md
        modified:   versioned_docs/version-2.0.0/operators/setup/install-node.md

[devendran-m]

Hi @mrkara , @KMCreatesWorlds ,
Could you review this PR and share your feedback/approval please?

[mrkara]

LGTM. Thank you!