chore(): Update licenses and update default image versions in helm values

[vtaskow]

What

Summary of changes

• Updated helm chart values in README.md:

make -C helm-charts/ install # to install helm-docs command
make -C helm-charts/ docs

• Pinned flatbuffers in the python folder since pip-licenses outputs UNKNOWN instead of the full license for the latest version from 2 days ago
• Manually added entries for dmitri.shuralyov.com/gpu/mtl and square/go-jose in the license_info.csv files of executor and operator, respectively; and also to the additional_license_info.csv. Now their full licenses are added to the respective license.txt files.
  ⚠️ This required to manually add those files and then run concatenate-license -o licenses/license.txt licenses/license_info.csv instead of make licenses.
• Marked the seldon-core-analytics as deprecated

Checklist

• Added/updated unit tests
• Added/updated documentation
• Checked for typos in variable names, comments, etc.
• Added licences for new files