Make "Perf Tips" feel more relevant

[InMatrix]

In a recent UX study of the perf tools, the participant (P06) didn't pay much attention to the performance tips served by the inspector. While there isn't a single reason leading to non-use of the tips, we can potentially introduce a few tweaks to make this section looks more relevant and useful:

• Change the section heading from "Perf Tips" to "Performance Warnings" or "Performance Advisories".
• Shorten the title of each item. For example "Performance considerations of Opacity Animation" can be shortened to "Opacity Animation". The section heading can provide the context to understand what the items are about.
• We could consider adding location of the first or most relevant instance of the widget the item is about to signal its relevance, e.g., "Opacity Animation spinning_box_demo.dart: L34"

[stevemessick]

@InMatrix Which version of the Flutter plugin were you using?

@jacob314 For design/coding consideration.

[InMatrix]

@stevemessick The latest version from last Friday and also the pre-release version @jacob314 and I are working on.

[devoncarew]

Some of these are doable by M31.

[magillus]

Also, it might be useful to detect lost frames and do popup/highlight at code which widget constructor was created too often.