Improve message text copying

[rasel-ml]

Checklist

• [x] I made sure that there are no existing issues - open or closed - to which I could contribute my information.
• [x] I made sure that there are no existing discussions - open or closed - to which I could contribute my information.
• [x] I have read the FAQs inside the app (Menu -> About -> FAQs) and my problem isn't listed.
• [x] I have taken the time to fill in all the required details. I understand that the request will be dismissed otherwise.
• [x] This issue contains only one feature request.
• [x] I have read and understood the contribution guidelines.

Feature description

Currently, to copy part of a message, the process is: Select Message → Three dot Menu→ Select Text

This is not very user-friendly.

A better approach could be:

• First long press to select the whole message.

• Then long press again to enter partial text selection (As In Telegram).

Sample Video:

https://github.com/user-attachments/assets/91ba3298-12da-4b2d-8c17-94c411c304c8

I belive this would make copying text much easier and more intuitive for users.