fix: params for oauth client manager

[aholovko]

This PR fixes the following issues:

• OAuth client manager uses values for grant_types_supported, response_types_supported and token_endpoint_auth_methods_supported from issuer's profile (OIDCConfig property). It's wrong as these values are supposed to be used when making calls to issuer's OIDC provider. VCS acts as an OIDC provider as well (e.g. for wallet) but it should use its own values here depending on what is actually implemented and supported (e.g. for grant_type only authorization_code and urn:ietf:params:oauth:grant-type:pre-authorized_code are supported).
• Support for client secret expiration is not implemented properly (i.e. it doesn't make sense to issue client ID with secret that will expire in 5 min) - so, for now, proposal is to create clients with secrets that never expire.

[codecov]

Codecov Report

Patch coverage: 100.00% and project coverage change: +0.05% 🎉

Comparison is base (c64c6af) 85.35% compared to head (abe113a) 85.40%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1414      +/-   ##
==========================================
+ Coverage   85.35%   85.40%   +0.05%     
==========================================
  Files         162      162              
  Lines       10234    10222      -12     
==========================================
- Hits         8735     8730       -5     
+ Misses       1092     1088       -4     
+ Partials      407      404       -3     

Files Changed	Coverage Δ
pkg/restapi/v1/oidc4ci/controller.go	90.05% <100.00%> (ø)
pkg/service/clientmanager/client_manager.go	95.65% <100.00%> (+4.31%)	⬆️

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