fix: tup-639 move c-button font-weight bold to cms

[wesleyboar]

Overview

All c-button font-weight bold to CMS.

Related

• TUP-639
• inspired by https://github.com/TACC/Core-Styles/pull/251#discussion_r1380667528
• requires https://github.com/TACC/Core-Styles/pull/253
• required by https://github.com/TACC/tup-ui/pull/364

Changes

• changed c-button font-weight to always be bold
• changed c-button styles to use custom selector

Testing & UI

See https://github.com/TACC/tup-ui/pull/364.

[wesleyboar]

Ideally, this PR also loads a new version of Core-Styles that includes https://github.com/TACC/Core-Styles/pull/253. But, I don't wanna update Core-Styles version from 2.11 to 2.19 not fully tested for all those changes just to avoid (a) some extra CSS and (b) not-yet-bold text. I'll update Core-CMS's version of Core-Styles in isolation just after merging this.