Add locale to commas decimal format

[iGabyTM]

Vault-Expansion/src/main/java/at/helpch/placeholderapi/expansion/vault/EconomyHook.java

Line 20 in c520fa4

private static final DecimalFormat COMMAS_FORMAT = new DecimalFormat("#,###");

For example, Romania uses #.###,## while USA uses #,###.##

[LordVardus]

That would be good if you could add that, it would look a lot better too

[SrBedrock]

Vault already provides a format method that can be used to format monetary values according to the economy configuration:
https://github.com/MilkBowl/VaultAPI/blob/8bad2c479f531436b4b0694f5696b501d0afef3e/src/main/java/net/milkbowl/vault/economy/Economy.java#L55-L62