Update label component hover style

Problem

Label component was added in !257 (merged), scoped label variant was added in !657 (merged), and style migration was added in !657 (merged). However, the hover style of the label and scoped label component is using wrong colors.

Proposal

Update the hover style and change the underline color with matching the color of the text.

Possible fix

Applying a dynamic class to gl-link in b3ce11fc could help.

Before	After