Add a encryption control character to the log lines

[APErebus]

Background

We identified an issue with #1047 where an automated upgrade would fail as the script pod would be created by an non-pod log encryption Tentacle, but then after the upgrade the pod log encryption Tentacle would fail as it expects all pod logs to be encrypted.

Results

We have added a new e to the log lines generated by the bootstrap runner. This control character indicates the line is encrypted. An absence of this control char (or being set to p) indicates that the line is in plaintext and should not be decrypted

This PR also include minor nit changes from the review of #1047

Shortcut story: [sc-98480]

How to review this PR

Quality :heavy_check_mark:

Pre-requisites

• [ ] I have read How we use GitHub Issues for help deciding when and where it's appropriate to make an issue.
• [x] I have considered informing or consulting the right people, according to the ownership map.
• [x] I have considered appropriate testing for my change.

[APErebus]

I will be testing this change in https://github.com/OctopusDeploy/helm-charts/pull/343 to verify that it behaves as expected

[APErebus]

I have validated locally that this build of Tentacle supports auto-upgrading via the Helm Chart integration tests