Improve I18N Issues (Based on 2.25.0)

There are several text domain issues which make UI strings display incorrectly, and modified codes are as the following.

\inc\installer\inc\admin.php

Line 44

__( "%s to install recommended SiteOrigin plugins and a SiteOrigin theme to get your site going.", 'siteorigin-panels' ),

Line 45

'<a href="' . esc_url( admin_url( 'admin.php?page=siteorigin-installer' ) ) . '" target="_blank" rel="noopener noreferrer" >' . __( 'Click here', 'siteorigin-panels' ) . '</a>'

Line 78 to 79

__( 'SiteOrigin', 'siteorigin-panels' ),
__( 'SiteOrigin', 'siteorigin-panels' ),

Line 90 to 91

__( 'Installer', 'siteorigin-panels' ),
__( 'Installer', 'siteorigin-panels' ),

Line 122

'activateText' => __( 'Activate', 'siteorigin-panels' ),

Actually, line 44 and 45 can be merged to one sentence.

__( '%1$sClick here%2$s to install recommended SiteOrigin plugins and a SiteOrigin theme to get your site going.', 'siteorigin-panels' ),
'<a href="' . esc_url( admin_url( 'admin.php?page=siteorigin-installer' ) ) . '" target="_blank" rel="noopener noreferrer" >','</a>'

inc\installer\tpl\admin.php

Line 5

<?php _e( 'SiteOrigin Installer', 'siteorigin-panels' ); ?>

Line 9 to 11

<li><a href="#" data-section="plugins"><?php echo __( 'Plugins', 'siteorigin-panels' ); ?></a></li>
<li><a href="#" data-section="themes"><?php echo __( 'Themes', 'siteorigin-panels' ); ?></a></li>
<li class="active-section"><a href="#" data-section="all"><?php echo __( 'All', 'siteorigin-panels' ); ?></a></li>

Line 45 to 46

__( 'Required %s', 'siteorigin-panels' ),
$item['type'] == 'plugins' ? __( 'Plugin', 'siteorigin-panels' ) : __( 'Theme', 'siteorigin-panels' )

Line 57

echo __( 'Plugin', 'siteorigin-panels' );

Line 59

echo __( 'Theme', 'siteorigin-panels' );

Line 75

<?php _e( 'Get SiteOrigin Premium', 'siteorigin-panels' ); ?>

Line 80

$text = __( 'Install', 'siteorigin-panels' );

Line 82

$text = __( 'Activate', 'siteorigin-panels' );

Line 88

$text = __( 'Update', 'siteorigin-panels' );

Line 98

<?php _e( 'Demo', 'siteorigin-panels' ); ?>

Line 104

<?php _e( 'Documentation', 'siteorigin-panels' ); ?>