Duplicate rebar type in the Rebar Profiles list

[Joanna Sangalang]

One type of rebar can be imported more than once in the Rebar Profiles list.

It would be better if each type of rebar can be imported only once so that there will not be too many types in the list or so as not to cause any confusion.

Also, it would be easier if rebars in Metric unit will be made available only in Projects in SI units and rebars in Imperial unit will be made available only in Projects in US units. With this, the user will not have too many options to choose from.