Some more minor issues with the rendering of bibliographical entries

This is to point out some more minor bugs with the output when rendering bibliographical entries (in addition to this older issue https://bibbase.userecho.com/communities/1/topics/6-minor-issues-with-the-rendering-of-bibliographical-entries that we didn't want to reopen).

Our bibbase file is here:

https://bibbase.org/show?bib=http%3A%2F%2Fwww.anton-webern.ch%2Fassets%2Fdocuments%2FAWG.bib&authorFirst=1&nocache=1&theme=simple

We recognized the following issues:

1) There seems to be an additional whitespace inside the "bibbase_paper_author" span. When adding a seperator like ":" with CSS ("bibbase_paper_author::after { content: ":"; }"), the result is

>> "NAME, S. :" instead of "NAME, S.:"

Is it possible to move the extra whitespace outside that span?

2) This extra whitespace in 1) also appears with an editor of a collection (@book):

>> NAME, S. , editor .

3) Note another extra whitespace after "editor" in 2) what leads to a strange gap with with multiple editors:

>> NAME1, S1.; and NAME2, S2. , editor s.

Probably this should rather be "editor(s)" like with @incollection?

4) missing seperator and space between series and publisher in @book class:

>> {{TITLE}}. Volume 1 of SeriesPublisher, Location, year.

(Could be something like "Series. Publisher, ...")

5) unnecessary(?) comma between series and volume in @incollection class:

>> {{TITLE}}, volume 1, of Series,

6) Note the different renderings of series/volume and leading seperators in 4) and 5).

Also +1 from our side for the custom citation style feature request. We have only recently started to use bibbase, because it is an amazing tool, but as we were told repeatedly from other academic projects the lack of customizable citation style is one of the main reasons why many people refuse to use bibbase. Or put another way, providing the possibility of customizable citation styles would, from our point of view, drastically increase the number of users even more, which would be fantastic.

Notwithstanding the above, thank you a lot for your excellent work!