Add stats to explore tab

[cristinamullin]

Is your feature request related to a problem? Please describe.

Incorporate TADA stats function into Explore Tab: https://usepa.github.io/TADA/reference/TADA_Stats.html

In table, include measurement count, location count, min, max, and percentile stats. Leave off the detailed censored data stats and suggested non-detect estimation method since those are already shown on the Censored Data tab. Include proportion of nondetects.

Mock up (outdated but still relevant):