[Feature] Server pagination implementation (#243)

## Major Changes
- Implement a REST style API app in epapi
- Currently implements a GET method for all entity types in the browse menu (both package level and global)
- Provides paginated results per default with query style filtering for reviewed vs unreviewed.
- Provides new paginated templates with thin wrappers per entity types for easier maintainability
- Implements e2e tests for the API

## Minor changes
- Added more comprehensive gitignore to cover coverage reports and other test/node.js etc. data.
- Add additional CI file for API tests that only gets triggered on API relevant changes.

## ⚠️ Currently only works with session-based authentication. Token based will be added in new PR.

Co-authored-by: Tim Lorsbach <tim@lorsba.ch>
Co-authored-by: jebus <lorsbach@envipath.com>
Reviewed-on: enviPath/enviPy#243
Co-authored-by: Tobias O <tobias.olenyi@envipath.com>
Co-committed-by: Tobias O <tobias.olenyi@envipath.com>

templates/components/loading-spinner.html

@@ -0,0 +1,11 @@
+<div class="benzene-spinner">
+  <svg viewBox="0 0 1000 1000" xmlns="http://www.w3.org/2000/svg">
+    <path
+      class="hexagon"
+      d="m 758.78924,684.71562 0.65313,-363.85 33.725,0.066 -0.65313,363.85001 z M 201.52187,362.53368 512.50834,173.66181 530.01077,202.48506 219.03091,391.35694 z M 510.83924,841.63056 199.3448,653.59653 216.77465,624.72049 528.2691,812.76111 z M 500,975 85.905556,742.30278 l 0,-474.94722 L 500,24.999998 914.09445,257.64444 l 0,475.00001 z M 124.90833,722.45834 500,936.15556 880.26389,713.69722 l 0,-436.15555 L 500,63.949998 124.90833,286.40833 z"
+      fill="black"
+      stroke="black"
+      stroke-width="2"
+    />
+  </svg>
+</div>