Mods to leverage @pega/auth package for authManager and configAccess …

[vrseraphin]

…core routines

Brings in a lot of the newer SDK-R related auth improvements:

• Support for obfuscating (transforming) session storage content (transform sdk-config.json param) and storing less auth configuration stuff in session storage
• Minimizing session storage content and providing control over whether auth and refresh tokens should be allowed to land in session storage or not (tokenStorage sdk-config.json param)
• Support for additional grantTypes customBearer, clientCreds, passwordCreds (and ability to use a different grant flow for portal vs mashup/embedded)
• Use of private class fields to better secure auth information in DOM

[vrseraphin]

Moving to less extensive approach by retaining server-config-service shell