Add support for three-digit gust reports

[SkySails]

Parsing the following (simplified) report yields a gust value of 4, which seems to be incorrect.

RKPM 091931Z 34028G043KT

I did some research, and while I found it hard to find "official" sources, I believe that I have found ones that are reputable enough. There also seems to be some degree of disagreement between sources, but I think it would be safe to support an extra digit regardless, as it seems that this does in fact occur in real reports.

Here are some extracts from a few sources with varying amounts of explicit specifications:

The maximum gust during the sampling period is reported when it exceeds the mean speed by 10 knots or more. It is indicated by the letter G which is followed by the gust value.
http://www.bom.gov.au/aviation/data/education/metar-speci.pdf

If gusts exceed the mean wind speed by 10kts or more in the 10 minutes preceding the time of the report, a letter G and 2 more figures are added to indicate the maximum wind speed
https://skybrary.aero/articles/meteorological-aerodrome-report-metar

Gf_mf_m will be included if gust speeds exceed the mean speed by 10 knots or more in the 10-minute period preceding the observation. If this condition is not met, Gf_mf_m is omitted. G indicates gusts and f_mf_m is the peak gust reported, using two or three digits as required.
https://meteocentre.com/doc/metar.html

This PR optionally includes a 3rd digit in the pattern match for gust values. I also added a test, and made sure that I did not break any of the existing ones!

[aeharding]

Hi! Thanks for the PR. It appears that there are some formatting issues.

[SkySails]

Sorry about that! For some reason, my editor did not pick up the Prettier config and I had to run it manually. It should be good now!

[SkySails]

Looks like it is now fixed upstream as well! Thanks for opening that issue!

[aeharding]

Should be fixed in 8.0.4! https://aeharding.github.io/metar-taf-parser/metar?input=RKPM+091931Z+34028G043KT