Use getters to avoid verbose nil checking

[antgamdia]

Description of the change

Follow-up PR based on #3376 (comment)

Benefits

Less verbosity for just building a log msg

Possible drawbacks

N/A

Applicable issues

N/A

Additional information

N/A

[absoludity]

+1. I wondered when I initially saw these why we don't instead use the go fmt built in support for quoting things to do something like:

Suggested change

	contextMsg := fmt.Sprintf("(cluster=[%s], namespace=[%s])", request.GetContext().GetCluster(), request.GetContext().GetNamespace())
	contextMsg := fmt.Sprintf("(cluster=%q, namespace=%q)", request.GetContext().GetCluster(), request.GetContext().GetNamespace())

But not necessary - just if you agree that'd be nicer (main reason for me is that it's clear that cluster and namespace a string values in the log output, as opposed to being arrays/slices of length 1).

[antgamdia]

I didn't change anything in the Fluxv2 plugin, since it is under heavy development and I don't want to interfere.
It is using different log messages (likelog.Infof("+fluxv2 GetInstalledPackageSummaries [%v]", request)), which isn't sth bad, but opens the discussion for ulterior issues like #3385