[Wallet] Fix 8 digit codes for mainnet

[i1skn]

Description

• Fix attestaion service URL, when / in the end is missing
• Remove firebase proxies.

Tested

Verification flow on Android device

Backwards compatibility

Yes

[gnardini]

Tested locally on mainnet and is working for me 😄

[nambrot]

Would note that Mainnet isn't the best testing ground for this as most validators haven't updated yet. So I'd probably recommend doing it on Alfajores as well

[i1skn]

@nambrot this PR specifically fix 8 digit codes on mainnet, on alfajores it works fine without this PR. Also, all validators on mainnet are on >= 1.1.0 version now.

[jeanregisser]

Thanks! 👍
Nice seeing one less dependency.

[jeanregisser]

Too bad JavaScript doesn't provide a builtin way to join url parts.

We do have a string helper though which does the same as what you did:

celo-monorepo/packages/sdk/base/src/string.ts

Lines 1 to 7 in 4276a18

	export function appendPath(baseUrl: string, path: string) {
	const lastChar = baseUrl[baseUrl.length - 1]
	if (lastChar === '/') {
	return baseUrl + path
	}
	return baseUrl + '/' + path
	}

[AlexBHarley]

Nested deep in the identity package we do https://github.com/celo-org/celo-monorepo/blob/master/packages/sdk/identity/src/offchain/utils.ts#L360.