Imports (micro-services)

[pouya-eghbali]

An import pattern should be added to the lexer, rules should be written for parser and generator, and the necessary runtime (if needed) should be created.

• Add import pattern in core/patterns.js
• Add from pattern in core/patterns.js
• Add parser rules in core/clio.beef
• Add generator rules in core/generator.js
• Add required builtins and runtime in core/internals

Import statement should work with below patterns:

import * from url
import name1 name2 name3 from url
import url
import name1 as name2 from url
import url as name

url means (http|ws)s?://.*

Related: #66
Another approach would be to parse path|url when generating and not on parse time, this'll save us from writing duplicated parser rules.

For beef files, there's a vscode addon hosted here:
https://github.com/pouya-eghbali/bean/tree/master/vscode-beef