[Bug]: Incorrect Implementation of onPressed for Locating Nearby Blood Banks (home_screen.dart)

The HomeCardConst widget used for locating nearby blood banks currently lacks a proper onPressed function implementation. This results in no action being taken when users attempt to use the "Locate Blood Banks" feature. The onPressed callback should navigate to the LocateBloodBanks screen but is either missing or incorrectly implemented.

### Expected behavior

This issue prevents users from accessing the "Locate Blood Banks" functionality, impacting their ability to find nearby blood donation centers through the app.Fix the onPressed callback for the HomeCardConst widget to properly navigate to the LocateBloodBanks screen.

Open home_screen.dart and locate the HomeCardConst widget used for the "Locate Blood Banks" feature. Trace the existing onPressed callback and the LocateBloodBanks screen reference. Done means tapping the card navigates to LocateBloodBanks instead of taking no action; verify the behavior in the app.

Written by the indexing model from the issue text.