feat: rename crate from rustfs-event-notifier to rustfs-event

This change simplifies the crate name to better reflect its core functionality
as the event handling system for RustFS. The renamed package maintains all
existing functionality while improving naming consistency across the project.

- Updated all imports and references to use the new crate name
- Maintained API compatibility with existing implementations
- Updated tests to reflect the name change

Cargo.lock

@@ -7452,7 +7452,7 @@ dependencies = [
  "rmp-serde",
  "rust-embed",
  "rustfs-config",
- "rustfs-event-notifier",
+ "rustfs-event",
  "rustfs-obs",
  "rustfs-utils",
  "rustls 0.23.27",
@@ -7490,7 +7490,7 @@ dependencies = [
 ]
 
 [[package]]
-name = "rustfs-event-notifier"
+name = "rustfs-event"
 version = "0.0.1"
 dependencies = [
  "async-trait",