Feature/remove legacy mongo

[Thadoy]

• Please check if the PR fulfills these requirements

• [*] The commit message describes your change
• [*] Tests for the changes have been added if possible (for bug fixes / features)
• [*] Docs have been added / updated (for bug fixes / features)
• [*] Changes are mentioned in the changelog (for bug fixes / features)

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)
  Tech update

• What is the current behavior? (You can also link to an open issue here)
  Dvalin mongodb uses the mongodb-driver-legacy.

• What is the new behavior (if this is a feature change)?
  Dvalin mongodb uses mongodb-driver-sync.
  The "new" Dvalin mongodb-legacy uses the mongodb-driver-legacy.

• Does this PR introduce a breaking change? (What changes might users need to make in their setup due to this PR?)
  There are braking changes with dvalin mongodb. To limit the impact, the old code was duplicated in mongodb-legacy.

A user would have to change their mongodb import to mongodb-legacy, if the choose not to migrate to the new code.

• Other information: