Minor cwl improvements for tcolorbox package (#3378)

* cwl: add `\thetcblayer`, tcolorbox counter repr

* cwl: two no-value key variants

completion/tcolorbox.cwl

@@ -204,6 +204,7 @@ library/all
 
 # << Layered Boxes and Every Box settings >>
 \tcbsetmanagedlayers{number}
+\thetcblayer
 
 # << Even and Odd pages >>
 \tcbifoddpage{odd code}{even code}
@@ -278,6 +279,7 @@ squeezed title*=%<text%>
 titlebox=#visible,invisible
 detach title
 attach title
+attach title to upper
 attach title to upper=%<text%>
 subtitle style={%<options%>}
 upperbox=#visible,invisible

completion/tcolorboxlibrarytheorems.cwl

@@ -41,6 +41,7 @@ terminator sign none
 label separator=%<separator%>
 theorem full label supplement={%<style%>}
 theorem label supplement={%<style%>}
+theorem hanging indent
 theorem hanging indent=##L
 theorem name and number
 theorem number and name