Summary

This PR fixes/implements the following bugs/features:

• Creating an OTP with an issuer/label that contains a space or other restricted characters does not properly escape the issuer/label

What existing problem does the pull request solve?**

Currently, if you create an OTP with an issuer that contains a space, for example:

var oneTimePassword = new OneTimePassword {
	Issuer = "Google Google",
	Label = "test@google.com",
	Secret = "pwq6 5q55"
};

and then call ToString on that oneTimePassword, that will return:

otpauth://totp/Google Google:test@google.com?secret=pwq65q55&issuer=Google%20Google

(note the first "Google Google" is not escaped, like the second one in the issuer parameter)

which then looks like this in Google Authenticator after scanning the resulting QR code:

This PR resolves this issue by correctly escaping both instances of the issuer in the URL, which then appears correctly in Google Authenticator:

otpauth://totp/Google%20Google:test@google.com?secret=pwq65q55&issuer=Google%20Google

Test plan

Test cases have been added.

Closing issues

N/A