Re-implemented guessing of next document id.

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

frontend/src/routes/document/PositionSelector.svelte

@@ -45,8 +45,7 @@
             description : description,
             amount      : 1,
             unit        : t('pieces'),
-            unit_price  : unit_price,
-            tax         : 0
+            unit_price  : unit_price
         });
     }
 

frontend/src/routes/document/TemplateSelector.svelte

@@ -1,8 +1,8 @@
 <script>
-    import {onMount} from 'svelte';
+    import {onMount}   from 'svelte';
 
-    import {api}     from '../../urls.svelte.js';
-    import {t}       from '../../translations.svelte.js';
+    import {api, post} from '../../urls.svelte.js';
+    import {t}         from '../../translations.svelte.js';
 
     let {
         caption,
@@ -16,11 +16,7 @@
 
     async function loadTemplates(){
         const url = api('document/templates');
-        var resp = await fetch(url,{
-            credentials : 'include',
-            method      : 'POST',
-            body        : JSON.stringify({company:company})
-        });
+        var resp = await post(url,{company:company});
         if (resp.ok){
             templates = await resp.json();
         } else {

frontend/src/routes/document/View.svelte

@@ -2,7 +2,7 @@
     import { onMount }       from 'svelte';
     import { useTinyRouter } from 'svelte-tiny-router';
 
-    import {api}             from '../../urls.svelte.js';
+    import { api, post }     from '../../urls.svelte.js';
     import { error, yikes }  from '../../warn.svelte';
     import { t }             from '../../translations.svelte.js';
     import { user }          from '../../user.svelte.js';
@@ -29,11 +29,7 @@
 
     async function addPosition(selected){
         const url  = api(`document/${doc.id}/position`);
-        const resp = await fetch(url,{
-            method      : 'POST',
-            credentials : 'include',
-            body        : JSON.stringify(selected)
-        });
+        const resp = await post(url,selected);
         if (resp.ok){
             doc.positions = await resp.json();
             yikes();