Default constructors of OIDC config builders should set correct default values

[sberyozkin]

Description

It is possible to build an individual OIDC config group with a group specific builder.
These group specific builders can be initialized from the main OidcTenantConfig builder, when they correctly pick up default values, for example, true for some boolean properties.
But, when the group specific builder is created with its default constructor, the correct default values are not set, requiring users calling additional builder methods

Implementation ideas

No response

[quarkus-bot]

/cc @pedroigor (oidc), @radcortez (config)

[michalvavrik]

just FYI, this already works for config in OIDC extension, just not for OIDC Common, Client and Registration, because I started doing what you describe later. so for example if you use constructor for builders defined directly in the OIDC extension, all should be fine. I'll look into fixing this.