Add screen hint to getAuthorizationUrl (#1001)

## Description

## Documentation

Does this require changes to the WorkOS Docs? E.g. the [API
Reference](https://workos.com/docs/reference) or code snippets need
updates.

```
[ ] Yes
```

If yes, link a related docs PR and add a docs maintainer as a reviewer.
Their approval is required.

src/user-management/__snapshots__/user-management.spec.ts.snap

@@ -6,6 +6,8 @@ exports[`UserManagement getAuthorizationUrl with a custom api hostname generates
 
 exports[`UserManagement getAuthorizationUrl with a provider generates an authorize url with the provider 1`] = `"https://api.workos.com/user_management/authorize?client_id=proj_123&provider=Google&redirect_uri=example.com%2Fauth%2Fworkos%2Fcallback&response_type=code"`;
 
+exports[`UserManagement getAuthorizationUrl with a screenHint generates an authorize url with a screenHint 1`] = `"https://api.workos.com/user_management/authorize?client_id=proj_123&provider=authkit&redirect_uri=example.com%2Fauth%2Fworkos%2Fcallback&response_type=code&screen_hint=sign-up"`;
+
 exports[`UserManagement getAuthorizationUrl with an organizationId generates an authorization URL with the organization 1`] = `"https://api.workos.com/user_management/authorize?client_id=proj_123&organization_id=organization_123&redirect_uri=example.com%2Fauth%2Fworkos%2Fcallback&response_type=code"`;
 
 exports[`UserManagement getAuthorizationUrl with no custom api hostname generates an authorize url with the default api hostname 1`] = `"https://api.workos.com/user_management/authorize?client_id=proj_123&provider=Google&redirect_uri=example.com%2Fauth%2Fworkos%2Fcallback&response_type=code"`;

src/user-management/interfaces/authorization-url-options.interface.ts

@@ -7,4 +7,5 @@ export interface AuthorizationURLOptions {
   provider?: string;
   redirectUri: string;
   state?: string;
+  screenHint?: 'sign-up' | 'sign-in';
 }

src/user-management/user-management.spec.ts

@@ -810,6 +810,21 @@ describe('UserManagement', () => {
   });
 
   describe('getAuthorizationUrl', () => {
+    describe('with a screenHint', () => {
+      it('generates an authorize url with a screenHint', () => {
+        const workos = new WorkOS('sk_test_Sz3IQjepeSWaI4cMS4ms4sMuU');
+
+        const url = workos.userManagement.getAuthorizationUrl({
+          provider: 'authkit',
+          clientId: 'proj_123',
+          redirectUri: 'example.com/auth/workos/callback',
+          screenHint: 'sign-up',
+        });
+
+        expect(url).toMatchSnapshot();
+      });
+    });
+
     describe('with no custom api hostname', () => {
       it('generates an authorize url with the default api hostname', () => {
         const workos = new WorkOS('sk_test_Sz3IQjepeSWaI4cMS4ms4sMuU');

src/user-management/user-management.ts

@@ -535,13 +535,20 @@ export class UserManagement {
     provider,
     redirectUri,
     state,
+    screenHint,
   }: AuthorizationURLOptions): string {
     if (!provider && !connectionId && !organizationId) {
       throw new TypeError(
         `Incomplete arguments. Need to specify either a 'connectionId', 'organizationId', or 'provider'.`,
       );
     }
 
+    if (provider !== 'authkit' && screenHint) {
+      throw new TypeError(
+        `'screenHint' is only supported for 'authkit' provider`,
+      );
+    }
+
     const query = toQueryString({
       connection_id: connectionId,
       organization_id: organizationId,
@@ -552,6 +559,7 @@ export class UserManagement {
       redirect_uri: redirectUri,
       response_type: 'code',
       state,
+      screen_hint: screenHint,
     });
 
     return `${this.workos.baseURL}/user_management/authorize?${query}`;