[UIK-4866] Small link/button-link underline style fix

[sheila-semrush]

Motivation and Context

• simplified underlining styles (moved underline slightly closer to text)
• removed bottom-padding — I think it's not needed now, but I'm not sure I remember correctly for which case it was added
• fixed text-decoration-thickness not applying in secondary button link
• added explicit size to some link examples (underlining is cropped without set line-height)

How has this been tested?

Manually.
Not uploading snapshots here because they haven't been updated in the parent branch, so they would contain some other changes apart from these.

Types of changes

• Bug fix (non-breaking change which fixes an issue).
• New feature (non-breaking change which adds functionality).
• Breaking change (fix or feature that would cause existing functionality to not work as expected).
• Nice improve.

Checklist:

• I have updated the documentation accordingly.
• I have added new tests on added of fixed functionality.

[ilyabrower]

why do you use text-decoration-line here and without -line in Link?

[sheila-semrush]

here text-decoration in the shorthand form caused text-decoration-thickness to not apply, in link there's no such problem, but we can do the same there for consistency. It's probably better to not mix shorthands and single attributes anyway

[sheila-semrush]

actually no, I was wrong, the problem with thickness was only in the secondary use, and what fixed it was removing text-decoration: underline from SButton[use='secondary'] SText due to order of rules. So I will roll back this change

[ilyabrower]

• removed bottom-padding — I think it's not needed now, but I'm not sure I remember correctly for which case it was added

Did you check it with ellipsis settings? It will enable overflow: hidden

[ilyabrower]

maybe it's better to remove this to render both links on the same line?

[sheila-semrush]

fixed