New test to check PKI AEF flog

        * error invalid_scope

        * error_description=One of the api names does not exist or is not associated with the aef id provided

## Test Case 28: Retrieve Security Context from AEF using PKI-secured API Invoker

**Test ID**:: ***capif_security_api-28***, ***smoke***

**Description**:

  Validate that the AEF can successfully retrieve the security context of an API Invoker when the selected security method is PKI and it contains CA root at ***authenticationInfo*** attribute inside securityInfo.

**Pre-Conditions**:

  * API Invoker is pre-authorised and Provider is also authorized

**Execution Steps**:

1. Register and onboard Invoker at CCF.

2. Register Provider at CCF, store certificates and Publish Service API **service_1** at CCF with only **PKI** as security method allowed.

3. Create Security Context indicating all security methods security methods as preferred in ***prefSecurityMethods*** attribute.

4. Retrieve Security Context by **AEF**.

**Information of Test**:

1. Perform [Invoker Onboarding] and [Provider Registration] 

2. Publish Service API at CCF:

     * Send **POST** to ccf_publish_url **https://{CAPIF_HOSTNAME}/published-apis/v1/{apfId}/service-apis**

     * body [service api description] with apiName **service_1**

       * apiName: **service_1**

       * securityMethods: **PKI**

     * Use **APF Certificate**

3. Create Security Context for this Invoker

     * Send **PUT** **https://{CAPIF_HOSTNAME}/trustedInvokers/{apiInvokerId}**

     * body [service security body]

         * prefSecurityMethods: **['PKI','PSK','OAUTH']**

     * Using **Invoker Certificate**.

     * Create Security Information Body with one **securityInfo** for each aef present at each serviceAPIDescription present at Discover.

4. Retrieve Service Security by AEF:

     * Sent GET **https://{CAPIF_HOSTNAME}/trustedInvokers/{apiInvokerId}?authenticationInfo=true&authorizationInfo=true**.

     * Query parameters ***authenticationInfo*** and ***authorizationInfo*** set to true.

     * Using **AEF Certificate**

**Expected Result**:

1. Response to Security Context Creation:

      1. **200 OK** response.

      2. body returned must accomplish **ServiceSecurity** data structure, with:

          *  ***selSecurityMethod*** inside ***securityInfo***: **PKI**

2. Response to GET Service Security:

      1. **200 OK** Response.

      2. body returned must accomplish **ServiceSecurity**

         1. ***securityinfo*** attribue only contains one item with ***authenticationInfo*** containing CA root.

  [Return To All Test Plans]: ../README.md

  [service security body]: ./service_security.json  "Service Security Request"