Add back "Powered by Esri" attribution

[gavinr-maps]

Describe the bug

Starting at Esri Leaflet v3.0.10, calling Util.setEsriAttribution(this._map) does not add the "Powered by Esri" attribution anymore.

https://github.com/Esri/esri-leaflet-static-basemap-tile/blob/59729d46c3fbafa1a56a1552ecaa7643b245c4f5/src/StaticBasemapTileLayer.js#L81C5-L81C40

So in this library we need to now add the "Powered by Esri" wording ourselves.

Reproduction

1. Esri Leaflet v3.0.10: https://jsbin.com/jiwiwem/edit?html,output

   • Expected: Attribution shows "Powered by Esri"
   • Actual: Attribution shows "Powered by Esri"

2. Esri Leaflet v3.0.13 (latest): https://jsbin.com/coruyum/1/edit?html,output

   • Expected: Attribution shows "Powered by Esri"
   • Actual: Attribution does not show "Powered by Esri"

Logs

No response

System Info

Leaflet: 1.9.4
Esri Leaflet: 3.0.13
Esri Leaflet Vector: 4.2.5

Additional Information

Originally reported by @sherylgiovanni: Esri/esri-leaflet#1396

To fix this, we can probably make a similar change to this: Esri/esri-leaflet-vector#229

[gowin20]

Fixed in https://github.com/Esri/esri-leaflet-static-basemap-tile/releases/tag/v1.0.0-beta.2