templates: add optional Series ID buttons to the patch list

[rossburton]

If the user has turned on display of patch IDs, add another column with the series IDs to the patch list template.

~Note that I've not tested this in production because I've not yet setup a local instance...~

[rossburton]

Now tested!

Had to use a nbsp to stop "Series ID" wrapping and ruining the header alignment.

[rossburton]

I'm torn on whether the column should just be called "ID" and let its position clarify what ID it refers to.

[rossburton]

Maybe the ID column should just be removed, and the button inline with the patch or series name?

[stephenfin]

I wonder if, rather than adding another column, we could add the <button> in the existing series column, before the subject? Every bit as clickable but we avoid adding yet more columns to the rather large table.

[rossburton]

Done.

Would it be sensible to merge the "Patch ID" and "Patch" columns too?

[rossburton]

The good thing about two columns is it forces the alignment...

[rossburton]

Polite ping