WebClient: cleanup some js code

also returns an error if file or directory names contain a slash
instead of silently replacing slashes with a similar symbol

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

templates/common/base.html

@@ -72,46 +72,13 @@ explicit grant from the SFTPGo Team (support@sftpgo.com).
 
 {{- define "basejs"}}
 <script type="text/javascript" {{- if .}} nonce="{{.}}"{{- end}}>
+    // https://developer.mozilla.org/en-US/docs/Web/API/Document/createTextNode
     function escapeHTML(str) {
         var div = document.createElement('div');
         div.appendChild(document.createTextNode(str));
         return div.innerHTML;
     }
 
-    function unescapeHTML(escapedStr) {
-        var div = document.createElement('div');
-        div.innerHTML = escapedStr;
-        var child = div.childNodes[0];
-        return child ? child.nodeValue : '';
-    }
-
-    function escapeHTMLForceSafe(str) {
-        return str
-            .replace(/&/g, '_')
-            .replace(/</g, '_')
-            .replace(/>/g, '_')
-            .replace(/\"/g, '_')
-            .replace(/\'/g, '_');
-    }
-
-    function fixedEncodeURIComponent(str) {
-        return encodeURIComponent(unescapeHTML(str)).replace(/[!'()*]/g, function (c) {
-            return '%' + c.charCodeAt(0).toString(16);
-        });
-    }
-
-    function replaceSlash(str){
-        return str.replace(/\//g,'\u2215');
-    }
-
-    function b64EncodeUnicode(str) {
-        return btoa(encodeURIComponent(str));
-    }
-
-    function UnicodeDecodeB64(str) {
-        return decodeURIComponent(atob(str));
-    }
-
     function fileSizeIEC(a,b,c,d,e){
         return (b=Math,c=b.log,d=1024,e=c(a)/c(d)|0,a/b.pow(d,e)).toFixed(1)
             +' '+(e?'KMGTPEZY'[--e]+'iB':'Bytes')