Collect icon names from svgPath directories and JSON maps (#20)

Without a `path`, AbstractIcon::path() falls back to `svgPath` for name
collection. IconCollection::buildMap() calls names() on construction, so
the fallback runs on every helper init, not only with checkExistence.

- FontAwesome4/5/6 (and so 7), Bootstrap and Material collectors fed an
  svgPath directory straight to file_get_contents(), raising
  "Read of N bytes failed with errno=21 Is a directory". They now scan
  the directory for .svg file names, like Lucide/Feather already did.
- A JSON SVG map as svgPath was rejected with "is not a directory",
  which buildMap() swallowed, silently disabling auto-prefixing (and
  failing hard with checkExistence). path() now accepts an existing
  .json map; the map keys are the icon names. FA4/Material read it as
  JSON, FA6 skips style detection for plain string map entries.
- The collector in-memory cache is a single static array shared by all
  subclasses and was keyed by path only, so two collectors reading the
  same path got each other's result. The key now includes the class.
- IconCollection defaults `separator` to ':' so it works standalone
  without IconHelper.

Validate icon names + drop dead Serializable from Html (#14)

Reject path-traversal payloads in SvgRenderTrait::getSvgPath and
HeroiconsIcon::getSvgPath: icon names are now allow-listed against
[a-zA-Z0-9][a-zA-Z0-9_-]*, the resolved path is realpath-confined to
the configured base directory, and the Heroicons style config key is
allow-listed against the directories Heroicons ships. JSON-map mode
also runs the icon-name allow-list defensively.

Drop the Serializable interface from View\Html. The legacy
unserialize(string): void method had an empty body and would have
left the typed $html property uninitialized on first access; PHP
8.1 deprecated the interface anyway. __serialize / __unserialize
remain and continue to round-trip cleanly.

Tests cover ../, slash, backslash and empty icon names plus the
Heroicons style allow-list.

Fix PHPStan.

Simpler svgPath config.

Add support for svg inlining (#7)

* Add support for svg inlining

* Added `Configure('debug')` checking support and auto inline when `false`
Added the `inline` argument to all icon classes for improved readability
Updated docs

* Improve inline regex functionality

* phpstan fix

Add SVG map support. (#4)

* Add SVG map support.

* Add SVG map support.

Add SVG support.

Remove deprecation usage

Caching icon collections.

Docs