chore: try to fix CodeQL failure "Polynomial regular expression"

Fix 1:
\d\.?\d* can backtrack catastrophically
\d(\.\d*)? is safer

Fix 2:
Useless parenthesis around "enc:"

Fix 3:
The httpTester regex was misleading. It did not really check for "http".
Simplified to show its true meaning. The behaviour should not have changed.

Signed-off-by: Martin d'Allens <martin.dallens@liberty-rider.com>

src/serve_rendered.js

@@ -23,8 +23,8 @@ import translateLayers from './translate_layers.js';
 
 const FLOAT_PATTERN = '[+-]?(?:\\d+|\\d+.?\\d+)';
 const PATH_PATTERN =
-  /^((fill|stroke|width)\:[^\|]+\|)*((enc:.+)|((-?\d+\.?\d*,-?\d+\.?\d*\|)+(-?\d+\.?\d*,-?\d+\.?\d*)))/;
-const httpTester = /^(http(s)?:)?\/\//;
+  /^((fill|stroke|width)\:[^\|]+\|)*(enc:.+|(-?\d+(\.\d*)?,-?\d+(\.\d*)?\|)+(-?\d+(\.\d*)?,-?\d+(\.\d*)?)*)/;
+const httpTester = /^\/\//;
 
 const mercator = new SphericalMercator();
 const getScale = (scale) => (scale || '@1x').slice(1, 2) | 0;