Refactor: Merge scr_event_log and scr_alert functions

[coderabbitai]

Description

Currently, the codebase has two separate functions for notifications:

• scr_event_log: Adds entries to the event log
• scr_alert: Creates alerts/popups for the player

These functions are often called consecutively with similar parameters, as they serve complementary purposes. For example, in scr_battle_count:

scr_alert(c_blue, "reward", $"{_text_choice.alert}");
scr_event_log(c_blue, $"{_text_choice.log}");

Proposed Solution

Merge these functions into a single function that handles both logging and alerts. This would:

1. Reduce code duplication
2. Ensure consistency between alerts and log entries
3. Simplify the API for developers

Related Links

• Raised in PR discussion: feat: Imperial Loyalty #635 (comment)

Requested by: @EttyKitty