input server_url_history implementation

[SandaruEARL]

Add URL History Dropdown to AddAccount Page

Description

• This PR improves the server URL input experience by adding a history dropdown that allows users to quickly select previously used server URLs. The dropdown is accessible via a history icon button in the text field and provides a clean interface for selecting past entries or clearing the history.

Changes

• Added ServerUrlHistory class to manage server URL history using SharedPreferences
• Implemented history dropdown UI with animated transitions
• Added ability to select history items with a single click
• Added option to clear history
• Ensured proper positioning and styling of the dropdown menu
• Fixed layout issues with the dropdown positioning

Implementation Details

• Used a Column layout approach instead of Stack/Positioned for better positioning
• Added smooth animations for dropdown appearance/disappearance
• Implemented proper scrolling for cases with many history items
• Added visual separation between text field and dropdown

Testing

• Tested on Samsung J7 prime(8.1 oreo)

[SandaruEARL]

• This PR improves the server URL input experience by adding a history dropdown that allows users to quickly select previously used server URLs. The dropdown is accessible via a history icon button in the text field and provides a clean interface for selecting past entries or clearing the history.

[chrisbobbe]

This isn't a change we've considered before; we don't have an issue for it in the tracker. Please start a new topic in #mobile in the Zulip development community explaining why this is needed.