Refactor some naming functions

[thorwhalen]

Consider this functions from meshed.util:

from meshed.util import (
    mk_func_name,
    find_first_free_name, 
    numbered_suffix_renamer, 
    replace_item_in_iterable
)
from i2.multi_object (
    name_of_obj,
    uniquely_named_objects,
)

They're all around the same "naming" eco system.
The first is to get a function name robustly, the two next ones are to handle duplicate names and the last can be used in this context, but also in a general "iterable editing" context.

There's also some similar functions in i2.

We should hunt these down, deduplicate, add some consistency, and make sure there's some appropriate docs for them.

Do they go in i2? Or partly i2 and partly meshed?

[thorwhalen]

Unchanged: mk_func_name, find_first_free_name, numbered_suffix_renamer, and replace_item_in_iterable are all still separate, standalone functions in meshed/util.py, same as when this was filed. No consolidation has happened. Related to #20/#29 (same naming/identity surface). Leaving open as backlog; no new evidence to add beyond confirming nothing's changed.