Pass unprefixed outputs of the same cell

[blaggacao]

Within a same cell, it is awkward to accessor the outputs of that same cell with the cellname's prefix.

inputs.self.packages.<system>.cellname-mypackage
# could become
inputs.cell.packages.<system>.mypackage

inputs.cell thereby has only cell-local meaning.

This avoids much of the magic that a mypackage is all of a sudden accessored as cellname-mypackage, which feels very suspicious in practice.

At the same time, externally the cell-prefixing, which is required for good encapsulation of concerns is preserved.

[blaggacao]

That could also eliminate the need for appending .__data for the data clade, since these values would be pre-metadata.

[blaggacao]

Also rename:

• inputs.self -> inputs.cells
• inputs.sourceInfo -> inputs.self

... to better reflect their actual scope.

Note: self has only the sourceInfo to block interaction over the global context with other inputs ("inputs shall be fully qualified")