Skip journal creation on import

[konalegi]

Adds option to disable journal creation on import. Since it's executed on each import that might save a lot of bandwidth, for our app it's around 20% of all requests.

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Before submitting the PR make sure the following are checked:

• [x] The PR relates to only one subject with a clear title and description in grammatically correct, complete sentences.
• [x] Wrote good commit messages.
• [x] Commit message starts with [Fix #issue-number] (if the related issue exists).
• [x] Feature branch is up-to-date with master (if not - rebase it).
• [x] Squashed related commits together.
• [x] Added tests.
• [x] Added an entry to the changelog if the new code introduces user-observable changes. See changelog entry format for details.

[konalegi]

@toptal-anvil ping reviewers