[beeswax] Escape HTML when printing field schema

This is simple to fix if you know python and mako framework.

If you create table with inner struct:

create table debug.escapeerror(
a struct<b:struct<c:float>>
);

Type of field A will printed "a(struct>)" bu should be "a(struct)"

https://github.com/cloudera/hue/blob/master/apps/beeswax/src/beeswax/templates/execute.mako

_column.html("<a href='javascript:void(0)' style='padding-left:10px'" + (col.comment != null && col.comment != "" ? " title='" + col.comment + "'" : "") + "><i class='fa fa-columns'></i> " + col.name + ($.trim(col.type) != "" ? " (" + $.trim(col.type) + ")" : "") + "</a>");