[TDF] Fix clashing of "a.b" and "a_b" columns
[TDF] Fix clashing of "a.b" and "a_b" columns

When the column name contains a dot, we replace it with an underscore
and use the modified name as corresponding variable name for jitted
Defines/Filters.
To avoid potential name clashes with pre-existing columns, the
modified name is now prefixed with "__tdf_arg_", as it was already
the case before the latest refactoring of jitting.

olifre/root,karies/root,karies/root,olifre/root,karies/root,olifre/root,karies/root,root-mirror/root,root-mirror/root,root-mirror/root,karies/root,olifre/root,karies/root,root-mirror/root,root-mirror/root,karies/root,olifre/root,root-mirror/root,olifre/root,karies/root,karies/root,olifre/root,root-mirror/root,olifre/root,olifre/root,root-mirror/root,root-mirror/root,olifre/root,root-mirror/root,root-mirror/root,karies/root,karies/root,olifre/root