Update title of the plan details page

[monsieur-z]

Changes proposed in this Pull Request

• Update the copy of the title in the plan/product details page
• Add top margin to the title

Testing instructions

• Visit the Plans section with the offer reset flow enabled
• Click on the button of the Jetpack Security card, and check that you land in the details page
• Check that the title mentions "Security"
• Back to the Plans page, click on the Jetpack Backup card
• In the details page, check that the title mentions "Backup"

Screenshots

Security

Backup

Mobile

[matticbot]

Test live: https://calypso.live/?branch=update/offer-reset-copy-tweaks

[matticbot]

Here is how your PR affects size of JS and CSS bundles shipped to the user's browser:

Sections (~181 bytes added 📈 [gzipped])

name             parsed_size           gzip_size
plans                 +319 B  (+0.1%)      +74 B  (+0.0%)
jetpack-connect       +319 B  (+0.0%)      +65 B  (+0.0%)
purchases             +187 B  (+0.0%)      +42 B  (+0.0%)

Sections contain code specific for a given set of routes. Is downloaded and parsed only when a particular route is navigated to.

Legend

What is parsed and gzip size?

Parsed Size: Uncompressed size of the JS and CSS files. This much code needs to be parsed and stored in memory.
Gzip Size: Compressed size of the JS and CSS files. This much data needs to be downloaded over network.

Generated by performance advisor bot at iscalypsofastyet.com.

[rcanepa]

Looks and works great!

[a8ci18n]

This Pull Request is now available for translation here: https://translate.wordpress.com/deliverables/4252529

Thank you @monsieur-z for including a screenshot in the description! This is really helpful for our translators.

[a8ci18n]

Translation for this Pull Request has now been finished.