Remove IDE Acceptance Rate from Daily Activity chart

[austenstone]

The IDE Acceptance Rate does not make sense in the Daily Activity chart and should be removed.

Plan:

1. Remove the "IDE Acceptance Rate" series from the daily-activity-chart.component.ts file. This will involve removing the series from the _chartOptions object and any related logic for calculating or displaying the data.
2. Remove the "IDE Acceptance Rate" calculation from the highcharts.service.ts file. This will involve removing the logic that calculates the acceptance rate from the transformMetricsToDailyActivityLine function.
3. Remove any related mappings in daily-activity-chart.component.ts such as targetMapping and typicalRangeMapping.