Separate options from client to make the responsibility more clear.

[yangshiqi]

Remove the magic number in the main function and define it as a constant.

What type of PR is this?

/kind feature

What this PR does / why we need it:
add kubeclient timeout parameter.
In our scenarios, biz logic needs to be coordinated with multi-node scheduling. When the nodes' number is large, the kube API's timeout must be controlled to prevent it from being stuck.

Which issue(s) this PR fixes:
Fixes # nope

Special notes for your reviewer:
Depends on PR #681
Base on this pr, I merged my version and splited the params according to the option feature of k8s, to separate the options-related extensions(maybe more like request/transports) from the client. I also isolated the default params in client, to prepare for the future needs of hami, and avoided the magic numbers.

Does this PR introduce a user-facing change?:
nope

[codecov]

Codecov Report

Attention: Patch coverage is 85.41667% with 7 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
pkg/util/client/client.go	72.00%	5 Missing and 2 partials ⚠️

Flag	Coverage Δ
unittests	64.91% <85.41%> (+17.93%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
pkg/util/client/options.go	100.00% <100.00%> (ø)
pkg/util/client/client.go	68.29% <72.00%> (+14.12%)	⬆️

... and 10 files with indirect coverage changes

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