PDO: Migrate maxlen of pdo_column_data from size_t to zend_long

[marc-mabe]

This is returned in PDOStatement::getColumnMeta as len documented as "The length of this column. Normally -1 for types other than floating point decimals."

Also, It was as FIXME already.

• pgsql: PQfsize: returns the space allocated for this column in a database row, in other words the size of the server's internal representation of the data type. (Accordingly, it is not really very useful to clients.) A negative value indicates the data type is variable-length.
• dblib: dbcollen: The maximum length, in bytes, of the data for the particular column. If the column number is not in range, dbcollen returns -1.
• firebird: XSQLVAR.sqllen -> ISC_SHORT -> signed short: length of data area
• mysql: MYSQL_FIELD.length
  • MYSQLND_FIELD.length -> zend_ulong: Width of column (create length)
  • libmysql: unsigned long length : Width of column (create length)

I noticed this during my work of 64bit integers on 32bit arch where it would was failing: https://github.com/php/php-src/actions/runs/16311803646/job/46068812948#step:9:2782