4.x: TLS default config values

[danielkec]

Fixes #8127

Helidon 2, 3

While in Helidon 2 and 3 following logic was used for sessionCacheSize and sessionTimeoutSeconds:

private long sessionCacheSize; // def 0
private long sessionTimeoutSeconds; //def 0
...
int sessionCacheSize = tlsConfig.sessionCacheSize();
if (sessionCacheSize > 0) {
  serverSessionContext.setSessionCacheSize(sessionCacheSize);
}
int sessionTimeoutSecs = tlsConfig.sessionTimeoutSeconds();
if (sessionTimeoutSecs > 0) {
  serverSessionContext.setSessionTimeout(sessionTimeoutSecs);
}

Resulting in an actual defaults being the unset defaults of SSLSessionContext:

• void setSessionTimeout(int seconds); ----> 86400
  seconds – the new session timeout limit in seconds; zero means there is no limit.
  The JDK implementation returns the session timeout as set by the setSessionTimeout method, or if not set, a default value of 86400 seconds (24 hours).

• void setSessionCacheSize(int size); ----> 20480
  size – the new session cache size limit; zero means there is no limit.
  The JDK implementation returns the cache size as set by the setSessionCacheSize method, or if not set, the value of the javax.net.ssl.sessionCacheSize system property. If neither is set, it returns a default value of 20480.

Helidon 4

In Helidon 4 we are currently using:

@ConfiguredOption("1024")
int sessionCacheSize();
@ConfiguredOption("PT30M")
Duration sessionTimeout();
...
SSLSessionContext serverSessionContext = sslContext.getServerSessionContext();
if (serverSessionContext != null) {
  serverSessionContext.setSessionCacheSize(tlsConfig.sessionCacheSize());
  serverSessionContext.setSessionTimeout((int) tlsConfig.sessionTimeout().toSeconds());
}

This PR alignes the defaults with previous versions of Helidon.