Replace print pdf icon

[SteelWagstaff]

This PR fixes #2264 and #2266

To test:

1. Produce a Print PDF export
2. Check to see that the new icon appears on the export page. The icon should have a red banner and should include the text 'Print PDF'

Note: I did not replace the 36 and 72 px versions of this image as they are not used anywhere in Pressbooks. The large size is explicitly specified for the export table, which is the only place these icons are currently used in Pressbooks:

pressbooks/inc/modules/export/class-table.php

Lines 414 to 416 in 86b921b

	protected function getIcon( $file, $size = 'large' ) {
	$file_class = $this->getCssClass( $file );
	$html = "<div class='export-file-icon {$size} {$file_class}' title='" . esc_attr( $file ) . "'></div>";

[codecov]

Codecov Report

Merging #2267 (d0a0b74) into dev (86b921b) will increase coverage by 0.07%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##                dev    #2267      +/-   ##
============================================
+ Coverage     68.40%   68.47%   +0.07%     
+ Complexity     4944     4928      -16     
============================================
  Files           132      131       -1     
  Lines         21363    21353      -10     
============================================
+ Hits          14613    14622       +9     
+ Misses         6750     6731      -19     

[SteelWagstaff]

@greatislander Is there a historical reason why we need to leave the small sizes of export icons SCSS

pressbooks/assets/src/styles/export.scss

Lines 96 to 198 in 86b921b

	&.small {
	width: 36px;
	height: 36px;
	background-size: 36px 36px;
	background-position: -0 0;
	background-repeat: no-repeat;
	&.epub {
	background-image: url(../images/epub-36.png);
	@include hidpi {
	background-image: url(../images/epub-72.png);
	}
	}
	&.epub3 {
	background-image: url(../images/epub3-36.png);
	@include hidpi {
	background-image: url(../images/epub3-72.png);
	}
	}
	&.icml {
	background-image: url(../images/icml-36.png);
	@include hidpi {
	background-image: url(../images/icml-72.png);
	}
	}
	&.mobi {
	background-image: url(../images/mobi-36.png);
	@include hidpi {
	background-image: url(../images/mobi-72.png);
	}
	}
	&.print-pdf {
	background-image: url('../images/print-pdf-36.png');
	@include hidpi {
	background-image: url('../images/print-pdf-72.png');
	}
	}
	&.pdf {
	background-image: url(../images/pdf-36.png);
	@include hidpi {
	background-image: url(../images/pdf-72.png);
	}
	}
	&.wxr {
	background-image: url(../images/wxr-36.png);
	@include hidpi {
	background-image: url(../images/wxr-72.png);
	}
	}
	&.vanillawxr {
	background-image: url(../images/vanillawxr-36.png);
	@include hidpi {
	background-image: url(../images/vanillawxr-72.png);
	}
	}
	&.xhtml {
	background-image: url(../images/xhtml-36.png);
	@include hidpi {
	background-image: url(../images/xhtml-72.png);
	}
	}
	&.htmlbook {
	background-image: url(../images/html5-36.png);
	@include hidpi {
	background-image: url(../images/html5-72.png);
	}
	}
	&.odt {
	background-image: url(../images/odt-36.png);
	@include hidpi {
	background-image: url(../images/odt-72.png);
	}
	}
	&.weblinks {
	background-image: url(../images/imscc-36.png);
	@include hidpi {
	background-image: url(../images/imscc-72.png);
	}
	}
	}

and the corresponding image assets in Pressbooks?

[fdalcin]

LGTM @SteelWagstaff

[greatislander]

@greatislander Is there a historical reason why we need to leave the small sizes of export icons SCSS and the corresponding image assets in Pressbooks?

@SteelWagstaff Nope. It used to be that the exports were displayed in a grid, with the most recent of each format as large icons and then a more compact grid with smaller icons below. These can and should be removed.

[SteelWagstaff]

@fdalcin Just pushed a commit which removes the unused small sizes of file export icons. If it still looks good to you, please squash and merge at your convenience.