fix: move non-sensitive data out of secrets.toml - BED-8838

[StranDutton]

Splits the BHE destination url out of secrets.toml and into config.toml, so that secrets.toml contains only credentials (token id and key), while config.toml holds non-sensitive config.

/resolves BED-8838

Note

This change is backward-compatible - existing collectors will still work if URL is left in secrets_<collector-name>.toml after the update. Read below to find relevant DLT documentation that confirms this behavior.

• Updated example enterprise configs (extension-specific and general secrets.toml / config.toml) to reflect changes.
• Updated comments in docker-compose.yml (for enterprise) to reflect changes.
• Updated Helm README and comments related to the change
• Also removed a stale reference to interval which needed to be removed
• Ran locally and confirmed behavior.

DLT Config Documentation - our situation applies to rule #4.
-> Previously, we referenced the BHE URL via dlt.secrets.value - this meant that value had to be defined as an env variable or inside of secrets.toml. Because of how secret injection works, our update to now grab the URL from dlt.config.value allows DLT to search through the 2 previously mentioned places (env variables and secrets.toml) in ADDITION to config.toml. As a result, the URL can now be defined in secrets.toml or config.toml. **One caveat ** is that if URL is that, if URL defined in both files, the one in secrets.toml will take precedence after this change due to DLT's hierarchy.