reorganize dialogs

[defnvary]

Introduces initial implementation of phase 3 of issue #2361

Description

This PR moves all *dialog.py files to a dialogs/ subfolder under views/ directory. There is no code change. it just changes the organization making future changes to views layer easier. The same can be done for tabs too.

Related Issue

#2361

Motivation and Context

This is a small part of a major refactor in the views layer of the current vorta application. Current /views is cluttered with tabs, dialogs, pages all in a single directory. There is plan to arrange them in respective folders, tabs under /views/tabs/, dialogs under /views/dialogs/.

How Has This Been Tested?

I am running Debian Linux. Used pytest with uv. Ran the following command in Python 3.14. Got 2 warnings unrelated to this change. All tests passed.

uv run pytest --ignore-glob="*darwin*.py"

Types of changes

• Reorganizes dialogs and related imports (UI, translation etc)

Checklist:

• I have read the CONTRIBUTING guide.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

I provide my contribution under the terms of the license of this repository and I affirm the Developer Certificate of Origin.

[m3nu]

What works well:

• Import rewiring is correct for all 6 moved modules
• .ts translation location references updated
• UI asset files moved to assets/UI/dialogs/
• Module alias (import extract as extract_dialog) preserves existing usage in archive_tab
• Tests updated

Issues to address:

1. Missing __init__.py — src/vorta/views/dialogs/ has no __init__.py. Works as a namespace package but is inconsistent with views/partials/ which has one.

2. exception.py imports get_asset from wrong module — line 11 uses from vorta.views.utils import get_asset, get_colored_icon. get_asset is defined in vorta.utils; it only resolves here because views/utils.py happens to re-import it. Other moved files (exclude.py, ssh.py) correctly import from vorta.utils.

3. 4 dialog modules not moved — export_window.py, import_window.py, repo_change_passphrase.py, and diff_result.py are all modal dialogs but remain in views/. This leaves dialogs split across two directories. Issue Refactor views: Add BaseTab class, ViewModel layer, and reorganize dialogs #2361 lists the first three explicitly; diff_result.py defines DiffResultDialog.

   Suggest moving all four into dialogs/ in this same PR so the reorganization is complete. Filenames can stay as-is (note import.py would collide with the keyword, so import_window.py is fine).