Add currency conversion setting

[EddWills95]

• Adds a currency selector for conversion and the logic to make the call to the manager in order to fetch the correct price
• Currently supports: "USD", "EUR", "GBP" (but could obviously any)

[louneskmt]

In the whole code, "Currency"or "Fiat Currency" sounds better to me than "Conversion Currency".

I also would not use the window local storage to store this user preference, but the user file. See this. I'm working on a commit to do that.

[louneskmt]

Just created 3 PRs relating to user settings : getumbrel/umbrel#302, getumbrel/umbrel-manager#58, #250.

Can you try use this code to set your Currency setting? I couldn't really test it, but It should work haha

[EddWills95]

I think it makes sense to hang tight for this PR: #250
Then I can build on top of it

[lukechilds]

What is this used for? I don't see where data is passed in to API.get(url, data) anywhere.

[louneskmt]

He added it to specify currency for the price route, but finally he chose to use query parameters instead of a data body. We should just discard these changes now.

[EddWills95]

Exactly

[louneskmt]

Also @lukechilds, we have a little issue we could not yet figure out how to solve. On the page load or reload, it seems that the getPrice action and currency conversion occurs before the settings state is set. It leads for example to a $NaN wallet balance in the vertical menu.

I think it comes from the fetchData DashboardLayout method, possibly because the getPrice action resolves before the getSettings one, so it cannot correctly fetch the price as the currency setting is not yet defined in the state:

umbrel-dashboard/src/layouts/DashboardLayout.vue

Lines 203 to 214 in e48061a

	fetchData() {
	this.$store.dispatch("system/getUnit");
	this.$store.dispatch("user/getSettings");
	this.$store.dispatch("bitcoin/getSync");
	this.$store.dispatch("bitcoin/getBalance");
	this.$store.dispatch("bitcoin/getTransactions");
	this.$store.dispatch("lightning/getSync");
	this.$store.dispatch("lightning/getTransactions");
	this.$store.dispatch("lightning/getChannels");
	this.$store.dispatch("bitcoin/getPrice");
	this.$store.dispatch("system/getAvailableUpdate");
	},

Maybe I'm wrong...

For the time being, I've set a return in case the currency is not defined:

umbrel-dashboard/src/store/modules/bitcoin.js

Lines 387 to 388 in e48061a

	const { currency } = rootState.user.settings;
	if(!currency) return;

But honestly I don't think it's the good solution (and it doesn't really solve the problem haha).

What do you think?