[bitnami/thanos] Add compactor dataDir setting

[gdlx]

Description of the change

Adds a dataDir compactor to customize the data directory.

Benefits

Allows the setting of a different data directory without overriding the whole args list.

Possible drawbacks

None

Applicable issues

Fixes #29835

Checklist

• [X] Chart version bumped in Chart.yaml according to semver. This is not necessary when the changes only affect README.md files.
• [X] Variables are documented in the values.yaml and added to the README.md using readme-generator-for-helm
• [X] Title of the pull request follows this pattern [bitnami/<name_of_the_chart>] Descriptive title
• [X] All commits signed off and in agreement of Developer Certificate of Origin (DCO)