Introduce more modern way of for parsing date/time/timestamp formats

[mlazdans]

Currently parsing ibase.timestampformat, ibase.dateformat, ibase.timeformat uses strptime(). It is deprecated by PHP, is not supported or does work differently on different platforms and missing features like fractions and proper time zone support. In case this function is not available, extension falls back to parsing of arbitrary format "%d%*[/]%d%*[/]%d %d%*[:]%d%*[:]%d" which is not documented.

Introduce fbrid.timestampformat, fbird.dateformat, fbird.timeformat and parse it with PHP date parsing facilities.

[mlazdans]

Format currently used by ibase.timestampformat, ibase.dateformat, ibase.timeformat are deprecated and is incompatible with current PHP date formatting.
strptime() - DEPRECATED as of PHP 8.1.0
strftime() - DEPRECATED as of PHP 8.1.0

I did some experimenting with parsing dates with format and functions used now by PHP and like the results - no locale dependency and same behaviour across Windows and Linux (and most likely with other platforms).

Not sure now about Introduce fbrid.timestampformat, fbird.dateformat, fbird.timeformat - this will just introduce extra complexity.

Any thoughts?

[mlazdans]

New features b76abda e611b4a

• Introduce ibase.timestampformat_tz and ibase.timeformat_tz INI etries
• Introduce new fetch constant IBASE_PHPDATE - fetch date/time fields as PHP Date object (tests needed)
• Drop strptime() / strftime() format, use https://www.php.net/manual/en/datetimeimmutable.createfromformat.php instead
• ibase.dateformat defaults to "Y-m-d"
• ibase.timeformat defaults to "H:i:s"
• ibase.timestampformat defaults to "Y-m-d H:i:s"
• ibase.timeformat_tz defaults to "H:i:s e"
• ibase.timestampformat_tz defaults to "Y-m-d H:i:s e"