Moves base aliases into attributes

- Base aliases are defined in a node sprout=>git=>base_aliases
- Adds empte attributes node called sprout=>git=>aliases for people to add custom aliases to in soloistrc
- adds fake aliases to soloistrc to help with testing
Removes default node attributes for authors and projects [#61519598]

As it would be wrong to install real git authors on someone's machine who did't
setup overrides in soloist rc, I am removing the default entries for this but
leaving examples in place for how to format them.
- Replaces Brian and Abhi's entries with Joe Blow and Jane A Smith and comments them out
- generifies and comments out default project entry
- Adds entries in soloistrc to help with testing