most points very slow in new version ,but old version is very good

* [ ] I've read, understood, and done my best to follow the [*CONTRIBUTING guidelines](https://github.com/jjatie/Charts/blob/master/CONTRIBUTING.md).

## What did you do?

ℹ In LineChartView , When there are most points on the graph, scaling with fingers will

Carlton and slow，in the last version . But The old version won't in such as 3.0.2.

## What did you expect to happen?

ℹ I wiss it will not solw in scaling with fingers in LineChartView if most points .

## What happened instead?

ℹ it is very slow in LineChartView if if most points scaling with fingers .

## Charts Environment

**Charts version/Branch/Commit Number:**
**Xcode version:*11.3*
**Swift version:*5.0*
**Platform(s) running Charts:**
**macOS version running Xcode:*10.15.2 *

## Demo Project

ℹ Please link to or upload a project we can download that reproduces the issue.