Add bucket_name variable

[aknysh]

what

• Add bucket_name variable

why

• Allow users to override the name of the created bucket instead of generating it from the context
• Useful in situations when a bucket needs to have a name without namespace, environment, name in it

references

• https://support.cloudflare.com/hc/en-us/articles/360037983412-Configuring-an-Amazon-Web-Services-static-site-to-use-Cloudflare

In order for the S3 bucket to proxy (not just basic CNAME) through Cloudflare, 
the bucket name has to match the domain.  
That way we can have the bucket completely behind Cloudflare and not exposed to the world, 
provided we added the policy to restrict access from Cloudflare's IP.

[aknysh]

/test all