Rename output submodules

[mishaturnbull]

Investigate renaming of the output submodules. from edgegraph.output import pyvis will mask the actual pyvis module and could cause confusion (will certainly cause confusion to IDEs which try to lint with the actual pyvis module).

Maybe rename the submodules to eg_to_<other>? Must be indicative of its purpose, but not mask the real module. Should be done before #34 .