support .http files

[tednaaa]

• ability to save request as .http

on save need to "append" request

• ability to select .http file and do requests from list

here is basic .http file syntax

@base=https://localhost:5167
 
### Create a new item
 
POST {{base}}/todoitems
Content-Type: application/json
 
{
  "id": "{{$guid}}",
  "name":"walk dog",
  "isComplete":false
}
 
### Get All items
 
GET {{base}}/todoitems
 
### Update item
 
PUT {{base}}/todoitems/1
Content-Type: application/json
 
{
  "id": 1,
  "name":"walk dog",
  "isComplete": true
}
 
### Delete item
 
DELETE {{base}}/todoitems/1