Make "These settings apply to the field everywhere it is used" clearer

Problem

Currently the field settings on every field contain the intro:

These settings apply to the Body field everywhere it is used.

For example, see admin/structure/types/manage/page/fields/body/field-settings

Consider, though, a situation where:

• we have a field field_description
• in node type Basic Page it is called "Main Area"
• in Article it is called "Description"
• in User it is called "Bio"
• In the taxonomy term Category it is called "Category Summary"
• In Article there is another, unrelated field field_xyz called "Main Area"

In the above example it is misleading to say, in admin/structure/types/manage/page/fields/field_description/field-settings, "These settings apply to the Main Area field everywhere it is used"

Proposed solution option 1

• Do not put, as a field label, the label of one of its random instances. (Fields have no label; field instances do).
• In admin/structure/types/manage/%/fields/%/field-settings, change the intro to something resembling what is in the enclosed image

Related: #1916738: Make it more obvious to those new to the concept of field translation that all instances of the field are translatable

Proposed solution option 2

To avoid cluttering the field settings page, provide a link to admin/reports/fields; and specify the field machine name instead of (or in addition to?) the label of one of its instances.