Use common Double Quotes for Columns

[MaikBusch78]

Fixes: no officially reported issue

Changes proposed in this pull request:

• column names in the style files are usually not quoted or double quoted there needed

Test rendering with links to the example places:

• tested with carto; the generated project.xml files before and after are identical

[imagico]

Same comments as in #4939 (review) apply. In addition - some guidance would be important describing when double quotes are required and when not.

[MaikBusch78]

Attribute quoting is needed iff the attribute name does not match the regex [a-zA-Z0-9_][a-zA-Z0-9_-]*, see here https://github.com/mapbox/carto/blob/305107201d4f8c4a2b9118c0077dde904f4224ed/build/tmlanguage_template.js#L50C78-L50C104.

[MaikBusch78]

I have also tested this change now. I produced a project.xml with carto project.mml > project.xml.1 before my change and after my change with carto project.mml > project.xml.2. Both project.xml files are identical (i used md5sum). I have also greped into the changed files to be sure that the input is really different.

[MaikBusch78]

So my own doubt that a rendering with the selector ['construction' = 'subway'] compared to a selector [construction = 'subway'] might be different, is at least for mapnik based rendering with a generated project.xml not valid.

[MaikBusch78]

@imagico What can i do to get your approval here too ?