Configure: rework build.info grammar and attributes

Configure: rework build.info grammar and attributes

The build.info grammar's regular expressions were a horrible read.
By assigning certain sub-expressions to variables, we hope to make
it a little more readable.

Also, the handling of build.info attributes is reworked to use a
common function instead of having copies of the same code.

Finally, the attributes are reorganized to specify if they belong with
programs, libraries, modules or scripts.  This will enable more
intricate attribute assignment in changes to come.

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/10088)