improve code readability

[cxljs]

• replace two similar functions appendUniqueNode and appendIfNotExists with a generic function.

• simplify the implementation of the get method in clusterNodes

• minimize line breaks in function definitions.

• keep the member name _generation of clusterNodes consistent with other types.

• rename a data member _masterAddr to masterAddr.

[ndyakov]

Hey @cxljs, thanks for your contribution.
Do you have a specific reason to prefer less linebrakes. I do think, sometimes multiline function declaration is better for readibility?
Those function declarations and the generic function for append are the only one that I am not so happy about including, but I see the benefit of having that generic...

[cxljs]

Hello @ndyakov , the reason for reducing line breaks is that there will be a comma after the last parameter, which often makes me think there are more parameters on the next line. e.g.:

func masterReplicaDialer(
	failover *sentinelFailover,
) func(ctx context.Context, network, addr string) (net.Conn, error) {

But this is just my personal opinion, if you think multiline function declaration is better for readibility, let's keep it as it is.

[ndyakov]

I do have a preference, but I am not the only person working on this :) @htemelski-redis , @ofekshenawa feel free to share your opinions.

[cxljs]

Oh, I missed this question yesterday - why don't you like the change to generic functions? My thought was that it could reduce one similar function definition and make the code cleaner. What's your perspective? There might be something I haven't considered, and your viewpoint would be really helpful to me.