fix: name new point layer using label if provided

[lixun910]

When creating a new point layer from a pair of {lat, lng} columns, the defaultName will be empty because of regex

const re = new RegExp(`(^|${specialCharacterSet})${suffixPair[0]}(${specialCharacterSet}|$)`);

and then falls back to name 'point':

This leads to many point layers with same label 'point', which are difficult to distinguish.

This PR tries to use the label value (if provided) first in this case.