fix(terra-draw-google-maps-adapter): allow use of @googlemaps/js-api-loader v2

[djw]

Description of Changes

• Allow use of @googlemaps/js-api-loader v2 in the Google Maps adapter. The lib and map objects passed to the adapter are identical, assuming the correct libraries are imported. importLibrary also populates the google.maps namespace (docs)
• Update storybook to use the v2 loader

Link to Issue

#692

PR Checklist

• The PR title follows the conventional commit standard
• There is a associated GitHub issue
• If I have added significant code changes, there are relevant tests
• If there are behaviour changes these are documented

[JamesLMilner]

Hey @djw - thank you for this! Appreciate your efforts here.

I'm just on my phone, but I just need to check, is this backwards compatible with v1? I.e. will this code change cause any breakages for people still on v1 do you know?

I will check it out later on my laptop when I get a moment.

[djw]

is this backwards compatible with v1?

Yes, the end result of the two loading processes is the same as far as the adapter is concerned — i.e. the google.maps namespace exists.