Use Conjur CLI v8.0

[szh]

Desired Outcome

Update demo to use CLI v8.0.

Implemented Changes

• Updated scripts and manifests to refer to the v8 Conjur CLI tag and use the updated command syntax.'
• Convert load_policies.sh script to use sh since new CLI container doesn't contain bash
• Use newly released version of the oss helm charts. (Depends on https://github.com/cyberark/conjur-oss-helm-chart/pull/180)

Connected Issue/Story

CyberArk internal issue ID: ONYX-33379

Depends on https://github.com/cyberark/kubernetes-conjur-deploy/pull/183

Changelog

• [ ] The CHANGELOG has been updated, or
• [x] This PR does not include user-facing changes and doesn't require a CHANGELOG update

Test coverage

• [ ] This PR includes new unit and integration tests to go with the code changes, or
• [x] The changes in this PR do not require tests

Documentation

• [x] Docs (e.g. READMEs) were updated in this PR
• [ ] A follow-up issue to update official docs has been filed here: [insert issue ID]
• [ ] This PR does not require updating any documentation

Behavior

• [ ] This PR changes product behavior and has been reviewed by a PO, or
• [ ] These changes are part of a larger initiative that will be reviewed later, or
• [x] No behavior was changed with this PR

Security

• [ ] Security architect has reviewed the changes in this PR,
• [ ] These changes are part of a larger initiative with a separate security review, or
• [x] There are no security aspects to these changes