refactor: move TLE text parsing into a portable source module

The satellites layer parsed catalog text inside its Cesium-backed orbit
owner. Move the parser unchanged to src/sources/tle.js, add a catalog
number helper, and have the layer delegate to it so code outside the
layer can read TLE text without loading rendering.

scripts/package-boundaries.json

@@ -922,6 +922,7 @@
       "src/data/issPass.js",
       "src/data/satelliteClass.js",
       "src/data/satellitePass.js",
+      "src/sources/tle.js",
       "src/layers/satellites/catalog.js",
       "src/layers/satellites/controls.js",
       "src/layers/satellites/index.js",
@@ -1659,6 +1660,7 @@
       "src/layers/satellites/labels.js",
       "src/layers/satellites/lifecycle.js",
       "src/layers/satellites/orbits.js",
+      "src/sources/tle.js",
       "src/layers/satellites/records.js",
       "src/layers/satellites/policy.js",
       "src/layers/satellites/rendering.js",
@@ -2323,6 +2325,7 @@
       "src/layers/satellites/labels.js",
       "src/layers/satellites/lifecycle.js",
       "src/layers/satellites/orbits.js",
+      "src/sources/tle.js",
       "src/layers/satellites/records.js",
       "src/layers/satellites/policy.js",
       "src/layers/satellites/rendering.js",