Str and number should work in same manner

Author: aaltat

atest/acceptance/keywords/content_assertions.robot

@@ -27,6 +27,11 @@ Page Should Contain
     Page Should Contain    This is the haystack
     Page Should Contain    non existing text
 
+Page Should Contain Numbers And String Should Be Same
+    Log Source
+    Page Should Contain    1
+    Page Should Contain    ${1}
+
 Page Should Contain With Text Having Internal Elements
     Page Should Contain    This is the haystack and somewhere on this page is a needle.
     Go to page "links.html"

atest/resources/html/index.html

@@ -7,5 +7,6 @@
 		<!-- this is a comment -->
 		<p>This is more text</p>
 		<span id="some_id">This text is inside an identified element</span>
+		<span>1</span>
 	</body>
 </html>

src/SeleniumLibrary/utils/__init__.py

@@ -20,7 +20,8 @@
 from .types import is_falsy, is_noney, is_string, is_truthy, WINDOWS  # noqa
 
 
-def escape_xpath_value(value):
+def escape_xpath_value(value: str):
+    value = str(value)
     if '"' in value and "'" in value:
         parts_wo_apos = value.split("'")
         escaped = "', \"'\", '".join(parts_wo_apos)