spack info: make sections optional; add build/stand-alone test information (#22097)

Add output of build- and install-time tests to info command

Enable dependencies, variants, and versions by default (i.e., provide --no* 
options; add gcc to test_info_fields to increase coverage for c_names->v_names

share/spack/spack-completion.bash

@@ -1157,7 +1157,7 @@ _spack_help() {
 _spack_info() {
     if $list_options
     then
-        SPACK_COMPREPLY="-h --help"
+        SPACK_COMPREPLY="-h --help -a --all --detectable --maintainers --no-dependencies --no-variants --no-versions --phases --tags --tests --virtuals"
     else
         _all_packages
     fi