Add test examples for the resource server sample

- Add a post endpoint in /messages
- Changes the security config to require the read scope to GET a message and the write scope
to POST a new message.
- Changes the jwks of the mock server so I could create a new access token with the write scope.
- Creates tests and integration-tests for the POST endpoint.
- Changes the README to add an example of a POST request.

Fixes gh-7118

samples/boot/oauth2resourceserver/README.adoc

@@ -44,7 +44,7 @@ Or import the project into your IDE and run `OAuth2ResourceServerApplication` fr
 Once it is up, you can use the following token:
 
 ```bash
-export TOKEN=eyJhbGciOiJSUzI1NiJ9.eyJzdWIiOiJzdWJqZWN0IiwiZXhwIjo0NjgzODA1MTI4fQ.ULEPdHG-MK5GlrTQMhgqcyug2brTIZaJIrahUeq9zaiwUSdW83fJ7W1IDd2Z3n4a25JY2uhEcoV95lMfccHR6y_2DLrNvfta22SumY9PEDF2pido54LXG6edIGgarnUbJdR4rpRe_5oRGVa8gDx8FnuZsNv6StSZHAzw5OsuevSTJ1UbJm4UfX3wiahFOQ2OI6G-r5TB2rQNdiPHuNyzG5yznUqRIZ7-GCoMqHMaC-1epKxiX8gYXRROuUYTtcMNa86wh7OVDmvwVmFioRcR58UWBRoO1XQexTtOQq_t8KYsrPZhb9gkyW8x2bAQF-d0J0EJY8JslaH6n4RBaZISww
+export TOKEN=eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJzdWJqZWN0IiwiZXhwIjoyMTY0MjQ1ODgwLCJhdXRob3JpdGllcyI6WyJST0xFX1VTRVIiXSwianRpIjoiMDFkOThlZWEtNjc0MC00OGRlLTk4ODAtYzM5ZjgyMGZiNzVlIiwiY2xpZW50X2lkIjoibm9zY29wZXMiLCJzY29wZSI6WyJub25lIl19.VOzgGLOUuQ_R2Ur1Ke41VaobddhKgUZgto7Y3AGxst7SuxLQ4LgWwdSSDRx-jRvypjsCgYPbjAYLhn9nCbfwtCitkymUKUNKdebvVAI0y8YvliWTL5S-GiJD9dN8SSsXUla9A4xB_9Mt5JAlRpQotQSCLojVSKQmjhMpQWmYAlKVjnlImoRwQFPI4w3Ijn4G4EMTKWUYRfrD0-WNT9ZYWBeza6QgV6sraP7ToRB3eQLy2p04cU40X-RHLeYCsMBfxsMMh89CJff-9tn7VDKi1hAGc_Lp9yS9ZaItJuFJTjf8S_vsjVB1nBhvdS_6IED_m_fOU52KiGSO2qL6shxHvg
 ```
 
 And then make this request:
@@ -61,10 +61,10 @@ Hello, subject!
 
 where `subject` is the value of the `sub` field in the JWT returned by the Authorization Server.
 
-Or this:
+Or this to make a GET request to /messages:
 
 ```bash
-export TOKEN=eyJhbGciOiJSUzI1NiJ9.eyJzdWIiOiJzdWJqZWN0Iiwic2NvcGUiOiJtZXNzYWdlOnJlYWQiLCJleHAiOjQ2ODM4MDUxNDF9.h-j6FKRFdnTdmAueTZCdep45e6DPwqM68ZQ8doIJ1exi9YxAlbWzOwId6Bd0L5YmCmp63gGQgsBUBLzwnZQ8kLUgUOBEC3UzSWGRqMskCY9_k9pX0iomX6IfF3N0PaYs0WPC4hO1s8wfZQ-6hKQ4KigFi13G9LMLdH58PRMK0pKEvs3gCbHJuEPw-K5ORlpdnleUTQIwINafU57cmK3KocTeknPAM_L716sCuSYGvDl6xUTXO7oPdrXhS_EhxLP6KxrpI1uD4Ea_5OWTh7S0Wx5LLDfU6wBG1DowN20d374zepOIEkR-Jnmr_QlR44vmRqS5ncrF-1R0EGcPX49U6A
+export TOKEN=eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJzdWJqZWN0IiwiZXhwIjoyMTY0MjQ1NjQ4LCJhdXRob3JpdGllcyI6WyJST0xFX1VTRVIiXSwianRpIjoiY2I1ZGMwNDYtMDkyMi00ZGJmLWE5MzAtOGI2M2FhZTYzZjk2IiwiY2xpZW50X2lkIjoicmVhZGVyIiwic2NvcGUiOlsibWVzc2FnZTpyZWFkIl19.Pre2ksnMiOGYWQtuIgHB0i3uTnNzD0SMFM34iyQJHK5RLlSjge08s9qHdx6uv5cZ4gZm_cB1D6f4-fLx76bCblK6mVcabbR74w_eCdSBXNXuqG-HNrOYYmmx5iJtdwx5fXPmF8TyVzsq_LvRm_LN4lWNYquT4y36Tox6ZD3feYxXvHQ3XyZn9mVKnlzv-GCwkBohCR3yPow5uVmr04qh_al52VIwKMrvJBr44igr4fTZmzwRAZmQw5rZeyep0b4nsCjadNcndHtMtYKNVuG5zbDLsB7GGvilcI9TDDnUXtwthB_3iq32DAd9x8wJmJ5K8gmX6GjZFtYzKk_zEboXoQ
 
 curl -H "Authorization: Bearer $TOKEN" localhost:8080/message
 ```
@@ -75,6 +75,20 @@ Will respond with:
 secret message
 ```
 
+In order to make a POST request to /message, you can use the following request:
+
+```bash
+export TOKEN=eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJzdWJqZWN0IiwiZXhwIjoyMTY0MjQzOTA0LCJhdXRob3JpdGllcyI6WyJST0xFX1VTRVIiXSwianRpIjoiZGI4ZjgwMzQtM2VlNy00NjBjLTk3NTEtMDJiMDA1OWI5NzA4IiwiY2xpZW50X2lkIjoid3JpdGVyIiwic2NvcGUiOlsibWVzc2FnZTp3cml0ZSJdfQ.USvpx_ntKXtchLmc93auJq0qSav6vLm4B7ItPzhrDH2xmogBP35eKeklwXK5GCb7ck1aKJV5SpguBlTCz0bZC1zAWKB6gyFIqedALPAran5QR-8WpGfl0wFqds7d8Jw3xmpUUBduRLab9hkeAhgoVgxevc8d6ITM7kRnHo5wT3VzvBU8DquedVXm5fbBnRPgG4_jOWJKbqYpqaR2z2TnZRWh3CqL82Orh1Ww1dJYF_fae1dTVV4tvN5iSndYcGxMoBaiw3kRRi6EyNxnXnt1pFtZqc1f6D9x4AHiri8_vpBp2vwG5OfQD5-rrleP_XlIB3rNQT7tu3fiqu4vUzQaEg
+
+curl -H "Authorization: Bearer $TOKEN" -d "my message" localhost:8080/message
+```
+
+Will respond this:
+
+```bash
+Message was created. Content: my message
+```
+
 == 2. Testing against other Authorization Servers
 
 _In order to use this sample, your Authorization Server must support JWTs that either use the "scope" or "scp" attribute._