Fixes https://github.com/chatwoot/chatwoot/issues/6228
There is a country code selector for the phone input field. This is
often a point of frustration. See the response below.
> We are using the phone number field however this can be frustrating
for customers, especially mobile users, to select the +1 US country
code. Our users are typically local businesses and being able to default
to +1 country code in the phone number field or the account would
improve the interaction they have with customers.
Most people who run local businesses don't need a country selector.
However, to preserve the quality of the data we store, we need a country
code.
A balance between these two issues can be found with an auto-populating
country code field based on the browser's timezone. This is what I did
in this PR. Based on the browser timezone, we will resolve it to the
closest country code.