chore(analysis/normed/group/basic): rename vars (#9652)
* use `E`, `F` for (semi)normed groups and greek letters for other
types;
* golf some proofs (`bounded_iff_forall_norm_le`, `norm_pos_iff'`);
* use `namespace lipschitz_with` and `namespace antilipschitz_with`
instead of manual prefixes for all lemmas;
* generalize `antilipschitz_with.add_lipschitz_with` to
`pseudo_emetric_space`;
* add `antilipschitz_with.edist_lt_top` and
`antilipschitz_with.edist_ne_top`;
* fix a typo in `pseudo_emetric_space.to_pseudo_metric_space`.
