Add config.yaml UI option to disable printing from replay banner

[tw4l]

Description

This PR adds a ui.disable_printing option to config.yaml which if set to any value with hide the new print replay iframe content button in the pywb 2.8 replay banner.

The second commit in this PR also modifies the VueUI.main() constructor to accept a JSON config object, to make the code a bit more readable and ease the addition of any future config options.

Motivation and Context

Commit https://github.com/webrecorder/pywb/commit/98be48d6e4f90116a9d07c6b979cdccf24c64036 adds a print button the replay banner but in some deployments (e.g. reading rooms) pywb administrators may want to disable this option.

Types of changes

• [ ] Replay fix (fixes a replay specific issue)
• [ ] Bug fix (non-breaking change which fixes an issue)
• [X] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [X] My change requires a change to the documentation.
• [X] I have updated the documentation accordingly.
• [ ] I have added or updated tests to cover my changes.
• [X] All new and existing tests passed.