feat: Enahnce pepper-sprite.yaml adding name entry

[erickzanardo]

Description

In the pepper-sprite.yaml file, we can do define the files like these:

files:
  - fileId: "Z8y1MP7R7z2u31aJq01N"
    output: "assets/images/buildings.png"
  - fileId: "w7Oy7gJXkBWUJgW7Y1jj"
    output: "assets/images/tiles.png"

I want to make it possible to add a name field too, like this:

files:
  - name: buildings
    fileId: "Z8y1MP7R7z2u31aJq01N"
    output: "assets/images/buildings.png"
  - name: tiles
    fileId: "w7Oy7gJXkBWUJgW7Y1jj"
    output: "assets/images/tiles.png"

This new field will not interfere with the exporting/processing since we already have an output field. The name field is also optional.

But it will be useful on the get command, where we should introduce a new parameter called --only [name]. Which when informed, we will download and process just the entry that matches the name