Add support for HijrahDate, JapaneseDate, MinguoDate and ThaiBuddhistDate

[jmiguelsamper]

They are all implementing classes of the java.time.temporal.Temporal interface.

[aparsons]

@jmiguelsamper I took a crack at what supporting HijrahDate could look like. I mainly looked for online documentation to put this together. This code allows for Hijrah dates to be parsed and formatted.

https://github.com/thymeleaf/thymeleaf-extras-java8time/compare/3.0-master...aparsons:hijrahdate-demo

[jmiguelsamper]

@aparsons looks very good, thank you for that. I will take a closer look to it and probably integrate it into the main code.

[danielfernandez]

Closing for now given lack of reported impact from users, in order to simplify towards integration in Thymeleaf core.