fix(form): verify nonce when changing payment method

[raftaar1191]

Issue Overview

Adding Nonce fields when changing the Gateway

Expected Behavior

Nonce Should add at the time of changing the Gateway

Current Behavior

Not using the Nonce

Steps to Reproduce (for bugs)

1. Create a Donation Form
2. Change the Gateway and see the network tab n the console in the Ajax you will see that nonce is not being passed to it

Related Issues and/or PRs

#2568
#2579

Todos

• Tests
• Documentation

WordPress Environment

``` ### WordPress Environment ###

Home URL: http://give.local
Site URL: http://give.local
WP Version: 4.9.1
WP Multisite: –
WP Memory Limit: 256 MB
WP Debug Mode: ✔
WP Cron: ✔
Language: en_US
Permalink Structure: /%postname%/
Show on Front: posts
Table Prefix Length: 3
Table Prefix Status: Acceptable
Admin AJAX: Inaccessible
Registered Post Statuses: publish, future, draft, pending, private, trash, auto-draft, inherit, refunded, failed, revoked, cancelled, abandoned, processing, preapproval, give_subscription

Server Environment

Hosting Provider: DBH: localhost, SRV: give.local
TLS Connection:
TLS Connection:
Server Info: nginx/1.10.1
PHP Version: 7.0.3
PHP Post Max Size: 1,000 MB
PHP Time Limit: 900
PHP Max Input Vars: 3000
PHP Max Upload Size: 1,000 MB
cURL Version: ❌ 7.38.0, OpenSSL/1.0.1t - We recommend a minimum cURL version of 7.40.
SUHOSIN Installed: –
MySQL Version: ❌ 5.5.55 - We recommend a minimum MySQL version of 5.6. See: WordPress Requirements
Default Timezone is UTC: ✔
fsockopen/cURL: ✔
SoapClient: ✔
DOMDocument: ✔
gzip: ✔
GD Graphics Library: ✔
Multibyte String: ✔
Remote Post: ✔
Remote Get: ✔

Give Configuration

Give Version: 2.0.0
Give Cache: Enabled
Database Updates: All DB Updates Completed.
Give Cache: Enabled
Give Cache: ✔New Donation✔Donation Receipt❌New Offline Donation❌Offline Donation Instruction✔New Donor Register✔Donor Register✔Email access
Upgraded From: –
Test Mode: Disabled
Currency Code: USD
Currency Position: Before
Decimal Separator: .
Thousands Separator: ,
Success Page: http://give.local/donation-confirmation/
Failure Page: http://give.local/donation-failed/
Donation History Page: http://give.local/donation-history/
Give Forms Slug: /donations/
Enabled Payment Gateways: Stripe - ACH, Test Donation, Stripe - Credit Card
Default Payment Gateway: Stripe - Credit Card
PayPal IPN Verification: Enabled
PayPal IPN Notifications: N/A
Admin Email Notifications: Disabled
Donor Email Access: Enabled

Session Configuration

Give Use Sessions: Enabled
Session: Disabled

Active Give Add-ons

Give - Email Reports: ❌ Unlicensed – by WordImpress – 1.0.1
Give - Fee Recovery: ❌ Unlicensed – by WordImpress – 1.3.5
Give - Form Field Manager: ❌ Unlicensed – by WordImpress – 1.2.4
Give - Manual Donations: ❌ Unlicensed – by WordImpress – 1.2.2
Give - PDF Receipts: ❌ Unlicensed – by WordImpress – 2.2.2
Give - Recurring Donations: ❌ Unlicensed – by WordImpress – 1.5
Give - Stripe Gateway: ❌ Unlicensed – by WordImpress – 1.5.2
Give - Tributes: ❌ Unlicensed – by WordImpress – 1.3.2

Other Active Plugins

Duplicate Post: by Enrico Battocchi – 3.2.1

Inactive Plugins

Give - 2Checkout Gateway: by WordImpress – 1.0.2
Give - Authorize.net Gateway: by WordImpress – 1.3.2
Give - AWeber: by WordImpress – 1.0.2
Give - Braintree Gateway: by WordImpress – 1.1.1
Give - CCAvenue Gateway: by WordImpress – 1.0
Give - ConvertKit: by WordImpress – 1.0.1
Give - CSV Toolbox: by WordImpress – 1.0
Give - Display Donors: by WordImpress, LLC – 1.0
Give - Dwolla Gateway: by WordImpress – 1.1.2
Give - Form Countdown: by WordImpress – 1.0
Give - Gift Aid: by WordImpress – 1.0.0
Give - Google Analytics Donation Tracking: by WordImpress – 1.1.1
Give - iATS Payment Solutions: by WordImpress – 1.0.1
Give - Paymill Gateway: by WordImpress – 1.1

Theme

Name: Twenty Sixteen
Version: 1.4
Author URL: https://wordpress.org/
Child Theme: No – If you're modifying Give on a parent theme you didn't build personally, then we recommend using a child theme. See: How to Create a Child Theme

</details>

[ravinderk]

Testing video: https://www.useloom.com/share/323aad8071854154b95504e54838f501