Feature/mst account

[Kron1749]

Description

• What does this PR do?
  Added functions to

1. Create MST account
2. Change name MST account
3. Delete MST account
4. Switch between MST and default account

• Why is this change needed?
  Users want MST

Type of change

• Bug fix
• New feature
• Refactor (cleaning up code without changing functionality)
• Documentation update
• Tests
• Other (describe below):

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Checklist

• Code adheres to coding guidelines and standards.
• Linting and formatting checks have passed, no local issues.
• Existing tests pass successfully, no local errors.
• Pull request is linked to a relevant issue or task.
• Tests are written for new features or fixes.
• Documentation has been updated (if applicable).

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Related Issue/Task

• Issue/Task link: [As a user, I'd like to use MST]

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Testing

• How has this been tested?
  • Describe manual testing steps or link to relevant automated tests.
• Edge cases covered:
  • List any specific cases handled by this PR.

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Screenshots/Video/Link to dedicated environment (if applicable)

• Include any visual examples of the change + dedicated environment (if there is a sort of automation).

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Additional Notes

• Add any information the reviewer should consider, especially cross-project impacts, UX changes, or potential risks.

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Reviewer Tasks

• Review logic for correctness and clarity.
• Verify that the code is following best practices.
• Test or review related areas if this PR affects other projects.