OpenID Connect support (#865)

* Added OpenID Connect support

Utilized Spring Security's OAuth2 respectively OIDC support as another
possibility to manage users and their permissions.

Signed-off-by: Brandon Schmitt <Brandon.Schmitt@kiwigrid.com>

* Document OpenID Connect Support

Signed-off-by: Brandon Schmitt <Brandon.Schmitt@kiwigrid.com>

* Updated license in OidcUserManagementAutoConfiguration.java

Signed-off-by: Brandon Schmitt <Brandon.Schmitt@kiwigrid.com>

* Revert updated license notice and add Kiwigrid license file

This reverts commit 23d36245

Signed-off-by: Brandon Schmitt <Brandon.Schmitt@kiwigrid.com>

* Resolve SonarQube issues

- Explicitly import the needed specific classes
- Document public methods
- Add `static` to the constant `JwtAuthoritiesOidcUserService.INVALID_REQUEST`
- Remove superfluous runtime exception `OAuth2AuthenticationException`

Signed-off-by: Brandon Schmitt <Brandon.Schmitt@kiwigrid.com>

* Add OidcUser support in SpringSecurityAuditorAware

Signed-off-by: Brandon Schmitt <Brandon.Schmitt@kiwigrid.com>

* Secure Management API using OpenID Connect, too.

Signed-off-by: Brandon Schmitt <Brandon.Schmitt@kiwigrid.com>

hawkbit-autoconfigure/src/main/resources/META-INF/spring.factories

@@ -13,5 +13,6 @@ org.eclipse.hawkbit.autoconfigure.scheduling.AsyncConfigurerAutoConfiguration,\
 org.eclipse.hawkbit.autoconfigure.scheduling.ExecutorAutoConfiguration,\
 org.eclipse.hawkbit.autoconfigure.security.SecurityAutoConfiguration,\
 org.eclipse.hawkbit.autoconfigure.security.InMemoryUserManagementAutoConfiguration,\
+org.eclipse.hawkbit.autoconfigure.security.OidcUserManagementAutoConfiguration,\
 org.eclipse.hawkbit.autoconfigure.web.WebMvcAutoConfiguration,\
 org.eclipse.hawkbit.autoconfigure.PropertyHostnameResolverAutoConfiguration