feat: add AUTH_INTERCEPTOR_BYPASS token for per-request bypass

[yogeshchoudhary147]

Description

Adds support for bypassing the AuthHttpInterceptor on a per-request basis using Angular's HttpContextToken pattern. This provides developers with dynamic, runtime control over token attachment without relying solely on
URL-based configuration.

Changes

• New export: AUTH_INTERCEPTOR_BYPASS - An HttpContextToken<boolean> for controlling interceptor behavior per-request
• Interceptor enhancement: Early bypass check in intercept() method that takes precedence over allowedList configuration
• Comprehensive tests: 9 new test cases covering all bypass scenarios and HTTP methods
• Documentation: Added new section in EXAMPLES.md with usage examples and common scenarios

Usage

import { HttpClient, HttpContext } from '@angular/common/http';                                                                                                                                                                        
import { AUTH_INTERCEPTOR_BYPASS } from '@auth0/auth0-angular';                                                                                                                                                                        
                                                                                                                                                                                                                                       
// Make a request without attaching an access token                                                                                                                                                                                    
this.http.get('/api/public', {                                                                                                                                                                                                         
  context: new HttpContext().set(AUTH_INTERCEPTOR_BYPASS, true)                                                                                                                                                                        
}).subscribe(data => {                                                                                                                                                                                                                 
  // Handle response                                                                                                                                                                                                                   
});                                                                                                                                                                                                                                    

Use Cases

• Public endpoints: Skip authentication for public APIs even when URL matches allowedList
• Dynamic control: Conditionally bypass based on runtime logic or application state
• Per-request override: Override global allowedList configuration for specific requests

Testing

• ✅ All existing tests pass (131 total)
• ✅ 9 new test cases covering bypass functionality
• ✅ Tested with GET, POST, PUT, DELETE, PATCH methods
• ✅ Verified interaction with allowAnonymous configuration
• ✅ Build verification confirms token is exported in public API

Breaking Changes

None. This is a completely additive feature that maintains full backward compatibility.

Checklist

• Code follows the project's coding standards
• Tests have been added/updated
• Documentation has been updated
• All tests pass locally
• No breaking changes

Fixes #658