Clean up indentation and whitespace inconsistencies in ecpg.

Clean up indentation and whitespace inconsistencies in ecpg.

ecpg's lexer and parser files aren't normally processed by
pgindent, and unsurprisingly there's a lot of code in there
that doesn't really match project style.  I spent some time
running pgindent over the fragments of these files that are
C code, and this is the result.  This is in the same spirit
as commit 30ed71e42, though apparently Peter used a different
method for that one, since it didn't find these problems.

Discussion: https://postgr.es/m/2011420.1713493114@sss.pgh.pa.us