feat: support multiple default values

[hitzhangjie]

This CL supports multiple default values like <proxy=cfg1|cfg2|cfg3>, this parameter will rendered like this in generateView:

--proxy=cfg1|cfg2|cfg3-----------|
|cfg1
|cfg2
|cfg3
|---------------------------------|

then we can use up/down arrow to select the wanted item, after press enter evaluateResult will be executed.

This CL also let the parameter view's title use larger width.

close #192

[hitzhangjie]

@knqyf263 Please review this PR. Thanks.

[hitzhangjie]

@knqyf263 Hi, could you take a little time to review this PR? I think this PR will solve the issue that some people encountered and suggested.

[RamiAwar]

@hitzhangjie Thanks for the PR! Will check this out! Really like the idea

[RamiAwar]

@hitzhangjie Interested in amending your PR to support the variable character proposal here https://github.com/knqyf263/pet/discussions/247#discussioncomment-8349705? 😁