Rename environment offerings

[dianadoherty]

Description of change

We want to rename environment offerings to the following:
Dedicated -> Private
Hosted -> Self-hosted

Fixes #232
Depends on: https://github.com/meroxa/meroxa-go/pull/88

Type of change

• New feature
• Bug fix
• Refactor
• Documentation

How was this tested?

• Unit Tests
• Tested in staging

Demo

Before this pull-request

meroxa env create --help
Create an environment

Usage:
  meroxa environments create NAME [flags]

Examples:

meroxa env create my-env \
	--type hosted \ 
	--provider aws \ 
	--region us-east-1 \ 
	--config '{\"aws_access_key_id\":\"my_access_key\", \"aws_secret_access_key\":\"my_secret_access_key\"}'

meroxa env create       
Environment name (optional): 
Type (hosted or dedicated): hosted
Cloud provider: aws
Region: us-east-1
✗ Does your environment require configuration: 
Environment details:
	Type: hosted
	Provider: aws
	Region: us-east-1

After this pull-request

meroxa env create --help
Create an environment

Usage:
  meroxa environments create NAME [flags]

Examples:

meroxa env create my-env --type self_hosted --provider aws --region us-east-1 --config "{\"aws_access_key_id\":\"my_access_key\", \"aws_secret_access_key\":\"my_secret_access_key\"}"

meroxa env create
Environment name (optional): 
Type (self_hosted or private): self_hosted
Cloud provider: aws
Region: us-east-1
✔ Region: us-east-1█
Environment details:
	Type: self_hosted
	Provider: aws
	Region: us-east-1

Additional references

Any additional links (if appropriate)

Documentation updated

Make sure that our documentation is accordingly updated when necessary.

You can do that by opening a pull-request to our (🔒 private, for now) repository: https://github.com/meroxa/meroxa-docs.

✨ In the future, there will be a GitHub action taking care of these updates automatically. ✨

Provide PR link: