Currency conversion: add XAG + XAU

[shivamgupta2020]

Added XAG+ XAU currency.
Tried to fix #2113

[shubhamkmr04]

It requires changes in stores/FiatStore.ts as well.
Have a look at #1960 for the reference

[shivamgupta2020]

For that, I was confused with what symbol should we use for XAG and XAU.
From what I searched, can we use Silver for XAG and Gold for XAU?

[shubhamkmr04]

Probably yes.
@kaloudis thoughts ?

For that, I was confused with what symbol should we use for XAG and XAU. From what I searched, can we use Silver for XAG and Gold for XAU?

[kaloudis]

Good, question: oz AU / oz AG since the price is in ounces? rtl true

[shubhamkmr04]

@shivamgupta2020 We have some failing tests in commits. Reset and force push them again

[kaloudis]

@shivamgupta2020 moving forward you may want to also cut PRs from a new branch, instead of master. It doesn't make a difference to us but it will be much easier for you if you're managing multiple contributions

[shivamgupta2020]

@shivamgupta2020 moving forward you may want to also cut PRs from a new branch, instead of master. It doesn't make a difference to us but it will be much easier for you if you're managing multiple contributions

I will take care of your advice in my future contributions. Thanks for your valuable input @kaloudis.