Change casing in admin bar for "Edit site"

[bronsonquick]

All other words in the admin bar use uppercase so we should change "Edit site" to be "Edit Site" for consistency. This was originally introduced in this ticket: https://core.trac.wordpress.org/changeset/52158

[sabernhardt]

Related discussions are on #60977 and #62368.

[audrasjb]

Hello and thank you for the ticket,

This change is different from the things pointed out by the related tickets @sabernhardt pointed out, so let's milestone it for 6.8.

[peterwilsoncc]

site-editor.php also includes the sentence case Edit site as a heading when the error message displays due to a lack of JavaScript (​code reference).

As all the other page headings in the dashboard use title case, let's change that too.

@audrasjb to aid translation teams, do you recommend a context be added to differentiate the page heading from the admin bar link?

[audrasjb]

Replying to peterwilsoncc:

@audrasjb to aid translation teams, do you recommend a context be added to differentiate the page heading from the admin bar link?

Yes this is 100% recommended in this case :)

[peterwilsoncc]

@bronsonquick Do you have time to fix the site heading and upload a new patch?

I recommend the following for each of the strings respectively

_x( 'Edit Site', 'site editor link from admin bar' )
_x( 'Edit Site', 'site editor heading' )

[adamsilverstein]

Related fix for "Collapse menu" -> "Collapse Menu" - https://core.trac.wordpress.org/ticket/59133

https://core.trac.wordpress.org/ticket/62971

[audrasjb]

In 59850:

Administration: Capitalize "Edit Site" strings for consistency.

This changeset brings more consistency by capitalizing the "Edit Site" strings located in the Toolbar and on the Site Editor screen.

Props bronsonquick, sabernhardt, audrasjb, peterwilsoncc, adamsilverstein.
Fixes #62971.