support fetching user insights reports

[mrmauer]

Tests

TKTK

After PR

You can now do any of the following...

report, err := auth.FetchUserTopInviterReport(
    &"30", // 30 days
    &propelauth.ReportPagination {
        PageSize: &10, // defaults to 10 for all reports
        PageNumber: &0, // defaults to 0 for all reports
    },
)

report, err := auth.FetchUserChampionReport(&"30")

report, err := auth.FetchUserReengagementReport(&"Weekly")

report, err := auth.FetchUserChurnReport(&"7")

report, err := auth.FetchOrgReengagementReport(&"Weekly")

report, err := auth.FetchOrgChurnReport(&"7")

report, err := auth.FetchOrgGrowthReport(&"30")

report, err := auth.FetchOrgAttritionReport(&"30")

timeseriesOfDailySignups, err := auth.FetchChartMetricData(
    "signups",
    &"Daily", // defaults to Daily if none provided
    &propelauth.ChartRange {
        StartDate: &"2026-01-01", // YYYY-MM-DD format, defaults to 30 days ago
        // EndDate defaults to today yesterday is the most recent data
    },
)