fix(rest): correctly resolve relative paths in REST requests

Axios seems to have a bug that manifests itself when the baseURL is defined with a path, e.g.
https://example.org/api/v1
Then, when an individual request is supposed to be sent to an absolute
path, e.g. /secure/oauth, Axios incorrectly resolves this combination as https://example.org/api/v1/secure/oauth
instead of https://example.org/secure/oauth
This change fixes this behaviour by relying on Nodejs built-in URL resolution: new URL(path, baseURL)

packages/rest/spec/screenplay/abilities/CallAnApi.spec.ts

@@ -75,11 +75,19 @@ describe('CallAnApi', () => {
     it('provides a way to determine the actual target URL the request will be sent to', () => {
         const callaAnApi = CallAnApi.at('https://example.org/api/v4');
 
-        const actualUrl = callaAnApi.resolveUrl({ url: 'products/3' });
+        const actualUrl = callaAnApi.resolveUrl({ baseURL: 'https://example.org/api/v4/', url: 'products/3' });
 
         expect(actualUrl).to.equal('https://example.org/api/v4/products/3')
     });
 
+    it('correctly resolves absolute URL paths', () => {
+        const callaAnApi = CallAnApi.at('https://example.org/api/v4');
+
+        const actualUrl = callaAnApi.resolveUrl({ baseURL: 'https://example.org/api/v4/', url: '/api/v5/products/3' });
+
+        expect(actualUrl).to.equal('https://example.org/api/v5/products/3')
+    });
+
     describe('when dealing with errors', () => {
 
         it('complains if you try to retrieve the last response before making an API call', () => {

packages/rest/src/screenplay/abilities/CallAnApi.ts

@@ -133,7 +133,10 @@ export class CallAnApi extends Ability {
      *  provided when the {@apilink Ability|ability} to {@apilink CallAnApi} was instantiated.
      */
     request(config: AxiosRequestConfig): Promise<AxiosResponse> {
-        return this.captureResponseOf(this.axiosInstance.request(config));
+        return this.captureResponseOf(this.axiosInstance.request({
+            ...config,
+            url: this.resolveUrl(config),
+        }));
     }
 
     /**
@@ -147,7 +150,9 @@ export class CallAnApi extends Ability {
      * @param config
      */
     resolveUrl(config: AxiosRequestConfig): string {
-        return this.axiosInstance.getUri(config);
+        return config.baseURL
+            ? new URL(config.url, config.baseURL).toString()
+            : config.url;
     }
 
     /**