fix: correctly parse years between 0 and 99. fixes #2550

[hanayashiki]

In the related issue, dayjs('0099-11-11').get('year') gets 1999 instead of 99.

However, in vanilla Date, it parses it correctly: new Date('0099-01-01').getUTCFullYear() === 99.

The reason lies in how we create the underlying Date object.

In new Date() of parseDate, when the first parameter is less than 99 and greater than 0, according to MDN:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date#date_components_and_time_zones

Note: Some methods, including the Date() constructor, Date.UTC(), and the deprecated getYear()/setYear() methods, interpret a two-digit year as a year in the 1900s. For example, new Date(99, 5, 24) is interpreted as June 24, 1999, not June 24, 99. See Interpretation of two-digit years for more information.

When d[1] is between 0 and 99, the year is interpreted as 1900 + d[1], thus we get 1999 instead of 99.

new Date(d[1], m, d[3]
        || 1, d[4] || 0, d[5] || 0, d[6] || 0, ms)

To fix this, I don't think it is possible to create a Date object with the correct year directly, so I add one line to set the year correctly. This is a little ugly, and better ideas welcome.