Replace OpenID Connect backend library

[michael-doubez]

What feature do you want to see added?

The backend library currently used is Google OAuth Client library which brings many issues:

• the library is in maintenance mode
• the code is primarily design to work for google API - features are hard to implement or checks prevents usage of library (see Login not working if alg field is missing in jwks_uri response #304 )
• the library is pulling dependencies which are not needed or desirable for Jenkins plugin - in particular some transistive dependencies are hard to specify right

Moving to a more generic library would allow restoring advanced checked bypassed in #308.

Spring security seems to have a decent support of openid connect and is more in line with Jenkins' dependencies.