Round the usage percentage to 1 decimal point

[Yingyingcheng]

Context

As described in #1044, the feature usage chart was displaying percentages with an excessive number of decimal places. We want to eliminate this visual noise and just show one decimal place.

Changes

• I updated webstatus-feature-usage-chart-panel.ts to use the toFixed() method to round usage percentages to 1 decimal place. Note that toFixed returns a string, so for valueExtractor, I had to convert it back to a number.
• Also updated webstatus-feature-usage-chart-panel.test.ts to update and add one test case to make sure the changes are covered in the tests.

[Yingyingcheng]

@jcscottiii please review my changes :) ! Seems like the workflows need your approval to run

[jcscottiii]

@Yingyingcheng thanks for the contribution! Can you make a common helper method named formatUsagePercentage that both the value extractor and tool tip extractor use?

Thanks for modifying both extractors by the way. If you only modified the tooltip, the value extractor would still have the raw value. Causing the graph to be potentially confusing compared to the value in the tooltip.

[jcscottiii]

FYI The playwright test for the feature page failed due to the new rounding of the values. You will need to regenerate the screenshots

[jcscottiii]

@Yingyingcheng Thanks for re-generating the screenshots.

Could you also take a look at this feedback in this comment:

Can you make a common helper method named formatUsagePercentage that both the value extractor and tool tip extractor use?

[Yingyingcheng]

@jcscottiii just updated, sorry! I forgot to commit the changes from that file