Rename @websocket:DispatcherMapping annotation to a more generic name for future extensibility

[chathushkaayash]

Purpose

Resolves ballerina-platform/ballerina-library#7839

Examples

@websocket:DispatcherConfig {
    dispatcherValue: "subscribe"
}
remote function onSubscribeMessage(Subscribe message) returns string {
    return "onSubscribeMessage";
}

Checklist

• Linked to an issue
• Updated the specification
• Updated the changelog
• Added tests
• Checked native-image compatibility

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 82.42%. Comparing base (8acf0c3) to head (54cb342).
Report is 9 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #1566      +/-   ##
============================================
- Coverage     82.45%   82.42%   -0.04%     
+ Complexity      603      602       -1     
============================================
  Files            48       48              
  Lines          3124     3124              
  Branches        415      415              
============================================
- Hits           2576     2575       -1     
  Misses          402      402              
- Partials        146      147       +1     

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud