Pinned pages containing the '+' character in their names are not correctly displayed on the document tree

Steps to reproduce

• Create a wiki page : "TestPage"
• Create a sub page under the "TestPage" page named "PageWith+Plus"
• Administrate the "TestPage" and add the sub page "PageWith+Plus" to the list of pinned pages and save. See screenshot :
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• Open the "TestPage" page and check the navigation panel

Expected results : On the document tree, only the sub page "PageWith+Plus" is displayed under the page "TestPage".

Current results : ** On the document tree, 2 pages are displayed under the "TestPage" :

• The "PageWith+Plus" page, which is expected
• Another non-existent page named "PageWith Plus". See screenshot :
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