improve code readability

[cxljs]

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

• simplify the implementation of the get method in clusterNodes.

• 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.

[htemelski-redis]

I am a bit on the fence about the function definitions.
I try to keep my lines shorter than 110-120 characters, and the proposed change is consistent with that.
On the other hand, for functions that accept more than a few arguments I preffer to separate them into new lines each

func (c cmdable) GeoRadiusByMember(
    ctx context.Context, 
    key, member string, 
    query *GeoRadiusQuery,
) *GeoLocationCmd {

[ndyakov]

I also do like what @htemelski-redis is suggesting.

[cxljs]

I've reverted the function definitions to their original format.

[ndyakov]

@cxljs Thank you for the contribution! This looks good.