feat: reverse shares (#86)

* add first concept

* add reverse share funcionality to frontend

* allow creator to limit share expiration

* moved reverse share in seperate module

* add table to manage reverse shares

* delete complete share if reverse share was deleted

* optimize function names

* add db migration

* enable reverse share email notifications

* fix config variable descriptions

* fix migration for new installations

frontend/src/components/share/FileSizeInput.tsx

@@ -0,0 +1,62 @@
+import { Col, Grid, NumberInput, Select } from "@mantine/core";
+import { useEffect, useState } from "react";
+import {
+  byteToUnitAndSize,
+  unitAndSizeToByte,
+} from "../../utils/fileSize.util";
+
+const FileSizeInput = ({
+  label,
+  value,
+  onChange,
+}: {
+  label: string;
+  value: number;
+  onChange: (number: number) => void;
+}) => {
+  const [unit, setUnit] = useState("MB");
+  const [size, setSize] = useState(100);
+
+  useEffect(() => {
+    const { unit, size } = byteToUnitAndSize(value);
+    setUnit(unit);
+    setSize(size);
+  }, [value]);
+
+  return (
+    <Grid align="flex-end">
+      <Col xs={6}>
+        <NumberInput
+          min={1}
+          max={99999}
+          precision={0}
+          variant="filled"
+          label={label}
+          value={size}
+          onChange={(value) => {
+            setSize(value!);
+            onChange(unitAndSizeToByte(unit, value!));
+          }}
+        />
+      </Col>
+      <Col xs={6}>
+        <Select
+          data={[
+            { label: "B", value: "B" },
+            { label: "KB", value: "KB" },
+            { label: "MB", value: "MB" },
+            { label: "GB", value: "GB" },
+            { label: "TB", value: "TB" },
+          ]}
+          value={unit}
+          onChange={(value) => {
+            setUnit(value!);
+            onChange(unitAndSizeToByte(value!, size));
+          }}
+        />
+      </Col>
+    </Grid>
+  );
+};
+
+export default FileSizeInput;