Big number visualization doesn't scale with widget width

[ale-cota]

Problem: We have an issue with big number visualisations - by default they are cutoff and resizing them takes up an unnecessary amount of space on the dashboard. They should resize to fit the size of the widget.

• feat(dashboards): Auto-size Big Number widget #76209
• chore(dashboards): Improve AutoSizedNumber instrumentation #76669
• chore(dashboards): Add manual duration measurement for AutoSizedText #76955
• chore(dashboards): Add basic spec for AutoSizedText #76995
• fix(dashboards): Fix Big Number rendering in Edit Mode #77097

[gggritso]

Re-opening this for tracking! It's still not in GA and I'm doing performance tests.

[gggritso]

👍🏻