Working user and link list, (big)restructure

This is now a workspace consisting of:
  * the pslink app (a wasm frontend for the admin interface)
  * the pslink binary
  * shared - modules for communication between the two above.

shared/src/apirequests/general.rs

@@ -0,0 +1,27 @@
+use std::ops::Deref;
+
+use serde::{Deserialize, Serialize};
+#[derive(Clone, Deserialize, Serialize, Debug, Default)]
+pub struct Filter {
+    pub sieve: String,
+}
+
+impl Deref for Filter {
+    type Target = String;
+
+    fn deref(&self) -> &Self::Target {
+        &self.sieve
+    }
+}
+
+#[derive(Clone, Deserialize, Serialize, PartialEq, Eq, Debug)]
+pub enum Ordering {
+    Ascending,
+    Descending,
+}
+
+#[derive(Clone, Deserialize, Serialize, Debug)]
+pub struct Operation<T, V> {
+    pub column: T,
+    pub value: V,
+}

shared/src/apirequests/links.rs

@@ -0,0 +1,31 @@
+use enum_map::{Enum, EnumMap};
+use serde::{Deserialize, Serialize};
+
+use super::general::{Filter, Operation, Ordering};
+
+/// A generic list returntype containing the User and a Vec containing e.g. Links or Users
+#[derive(Clone, Deserialize, Serialize, Debug)]
+pub struct LinkRequestForm {
+    pub filter: EnumMap<LinkOverviewColumns, Filter>,
+    pub order: Option<Operation<LinkOverviewColumns, Ordering>>,
+    pub amount: usize,
+}
+
+impl Default for LinkRequestForm {
+    fn default() -> Self {
+        Self {
+            filter: EnumMap::default(),
+            order: None,
+            amount: 20,
+        }
+    }
+}
+
+#[derive(Clone, Deserialize, Serialize, Debug, PartialEq, Eq, Hash, Enum)]
+pub enum LinkOverviewColumns {
+    Code,
+    Description,
+    Target,
+    Author,
+    Statistics,
+}

shared/src/apirequests/mod.rs

@@ -0,0 +1,3 @@
+pub mod general;
+pub mod links;
+pub mod users;

shared/src/apirequests/users.rs

@@ -0,0 +1,28 @@
+use enum_map::{Enum, EnumMap};
+use serde::{Deserialize, Serialize};
+
+use super::general::{Filter, Operation, Ordering};
+
+#[derive(Clone, Deserialize, Serialize, Debug)]
+pub struct UserRequestForm {
+    pub filter: EnumMap<UserOverviewColumns, Filter>,
+    pub order: Option<Operation<UserOverviewColumns, Ordering>>,
+    pub amount: usize,
+}
+
+impl Default for UserRequestForm {
+    fn default() -> Self {
+        Self {
+            filter: EnumMap::default(),
+            order: None,
+            amount: 20,
+        }
+    }
+}
+
+#[derive(Clone, Deserialize, Serialize, Debug, PartialEq, Eq, Hash, Enum)]
+pub enum UserOverviewColumns {
+    Id,
+    Email,
+    Username,
+}