Proj4 upgrade and include support for "Grid Based Datum Adjustments"

[rowheat02]

Description

This issue is intended to:

• update proj4 to latest version(skip old custom repo for proj4)
• include support for "Grid Based Datum Adjustments"
  • For higher accuracy using grid correction in coordinate transformations
  • Support for NTV2 format (.gsb) and GeoTIFF format (.tif)

Other useful information

• Reference docs for proj4: https://www.npmjs.com/package/proj4
• update the docs too on mapstore

Grid file supports on mapstore

1. Host the grid file on an external server
2. configure them in localConfig.json with paths and type.
3. MapStore2 loads them when the app starts
4. proj4js registers them so it knows what @GRIDNAME refers to
5. When someone uses a projection that references a grid (like +nadgrids=@PENR2009), proj4 applies the high-accuracy corrections