fix(update): check all releases to support prereleases & drafts

[altaskur]

This pull request updates the update-checking logic and its tests to support fetching and handling multiple GitHub releases, specifically filtering out draft releases. This ensures that only published (non-draft) releases are considered for updates, improving the reliability of the update feature.

Update logic improvements:

• Changed the GitHub API endpoint in UpdateService from fetching only the latest release to fetching all releases, allowing more control over which releases are considered.
• Updated the logic in checkForUpdates to filter out draft releases and select the most recent non-draft release as the latest available version.
• Modified the returned update information to use the selected non-draft release's details.

Type and test updates:

• Added draft and prerelease fields to the GitHubRelease interface and updated all test mocks to include these fields. [1] [2] [3] [4] [5]
• Updated tests to mock the API response as an array of releases, and added a new test to verify that draft releases are ignored by the update logic. [1] [2] [3] [4]