Make Launch environments independent from Properties

[#1]

It will be highly flexible if the Launch properties could be mapped and remapped to Environments (embed codes).

The benefits:

- no need to contact website dev team to update the embed codes

- easy to fix an issue if a wrong embed code is added to the page (website)

- easy to merge the implementation on several websites into one property or vice versa to split websites among various properties

How would the analytics developer/ architect work with this feature:

1. Create environments one per website/ domain/ website environment/ app

2. Ask the web team to add the embed codes

3. Manage the environments mapping in the Launch UI