Add sending email for VPN support from VPN settings panel

[rebron]

Test plan

See #15804

Description

VPN users need a way to contact us for support issues. We should match the current designs for mobile with an email form
To: brave at guardianapp.com
From: user, prefilled
Subject: Brave Firewall + VPN Issue

Users should be able to select from the following options:

• Cannot connect to the VPN (Other error)
• No internet when connected
• Slow connection
• Website doesn't work
• Other

Design

Help needed specifically with how the options should look! 😄

We can wire up here:

[jenn-rhim]

@aguscruiz ^

[aguscruiz]

@rebron are we using a mailto link after the user selects the subject? Or can we add something more complex like an inline form on the popup itself?

I'm thinking something like this, if we can:

[bsclifton]

Updated picture from Figma 😄

Thanks @aguscruiz!

[stephendonner]

Verified PASSED using 1.39.84 on Windows 10

Confirmed successful VPN sign-in, log-in, and technical-support form submission.

Steps:

1. install 1.39.84
2. launch Brave using --vmodule="*/skus/*"=1 --enable-logging=stderr
3. via brave://flags, set Enable experimental SKU SDK to Enabled
4. set Experimental SKU Environment to Development
5. also set Brave Experimental VPN to Enabled
6. click to Relaunch
7. load account.brave.software
8. enter basic auth creds for site
9. enter an email and click Get login link
10. check your email inbox
11. click Log in to Brave or the link in the email
12. click on Browse plans
13. scroll down and click on Buy now for Brave VPN Subscription
14. enter payment details on https://checkout.stripe.com/pay/cs_test…
15. click Subscribe
16. you should get a Complete your purchase... screen
17. click on Complete payment
18. click on the VPN icon
19. click on Settings
20. click on Contact technical support
21. fill out the form
22. click Submit

Submitted	Dark mode	Received From Guardian

(They are looking at the hostname showing city, as a bug.)

[stephendonner]

Verified PASSED using

Brave	1.39.108 Chromium: 101.0.4951.67 (Official Build) beta (x86_64)
Revision	8888ee7a24e2c36661ddb9536c35b7d4852a3a98-refs/branch-heads/4951@{#1230}
OS	macOS Version 12.5 (Build 21G5027d)

Followed my original steps to reproduce, and cross-confirmed again with Guardian that they received my 3 test submissions: https://bravesoftware.slack.com/archives/C0141L60REG/p1653176119435419.

[stephendonner]

Logged:

• Contact technical support form doesn't dismiss after submission #22731
• Hostname field in submitted user-support data to Guardian lists city, rather than actual hostname #22628