[RAV] Support .env file

[illiakovalenko]

Description / Motivation

• Added .env file support
• Each bootstrap command uses dotenv, in order to have access to environment variables if running any command without jss command
• Whenever it's possible use constants
• Whenever it's possible use temp config file, as it has access to environment variables and to the values from package.json
• Removed @sitecore-jss/sitecore-jss package from angular sample, as we should use sitecore-jss-angular
• Use both graphql and rest services in order to have ability to switch fetch method
• Dynamically enable debug logging for react and vue samples, as they have different environment variables naming convention

Testing Details

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

[ambrauer]

Looks great, see just a few comments

[ambrauer]

👍