Editor mode implemented

[DK318]

Description

An [-e|--edit] implementation. It opens a temporary file where you see TOML-like representation of an entry. Also, I've made entry path in CreateOptions parser optional argument.

Related issue(s)

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Related changes (conditional)

• Tests

  • [x] If I added new functionality, I added tests covering it.
  • [ ] If I fixed a bug, I added a regression test to prevent the bug from silently reappearing again.

• Documentation

  • [x] I checked whether I should update the docs and did so if necessary:
  • README
  • Haddock

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  • [x] Any modifications of public contracts comply with the Evolution of Public Contracts policy.
  • [x] I added an entry to the changelog if my changes are visible to the users and
  • [x] provided a migration guide for breaking changes if possible

Stylistic guide (mandatory)

• [x] My commits comply with the policy used in Serokell.
• [x] My code complies with the style guide.