Single WavefrontClient.Builder constructor to specify any auth type

[oppegard]

A new constructor for clearly choosing the type of authentication desired when creating a WavefrontClient:

public Builder(String server, TokenService.Type tokenType, String multiPartToken)

Examples of the four supported authentication types:

Proxy

WavefrontClient.Builder("http://wf-proxy.local:2878",
    TokenService.Type.NO_TOKEN,
    null)

Wavefront API Token

WavefrontClient.Builder("https://surf.wavefront.com",
    TokenService.Type.WAVEFRONT_API_TOKEN,
    "<wf-api-token-guid>")

CSP Client Credentials

WavefrontClient.Builder("https://surf.wavefront.com",
    TokenService.Type.CSP_CLIENT_CREDENTIALS,
    "clientId=<client-id>,clientSecret=<secret>,orgId=<optional-org-id>")

CSP User API Token

WavefrontClient.Builder("https://surf.wavefront.com",
    TokenService.Type.CSP_API_TOKEN,
    "<csp-user-api-token>")

This feature is to unblock micrometer-metrics/micrometer#4054 and spring-projects/spring-boot#37165.

Other Notes

• Fixed a bug where maxQueueSize was incorrectly defaulted to 500,000. It is now 50,000 and matches our README as well as the same default used in wavefront-sdk-go and wavefront-sdk-python.
• Removed cspBaseUrl parameter from constructors of WavefrontClienter.Builder. Overridding the Production CSP URL can be done with the existing the cspBaseUrl(String url) method.

[ginwoopak]

Looks good! Left one comment on the TODO.