Trie update

General update, based what on [bug 5892](https://bugs.alliedmods.net/show_bug.cgi?id=5892) (SourceMod) by David.

- Removed KTrie dependency to Hash map
- Added new natives, including iterators:
    * ```TrieGetSize```
    * ```TrieSnapshotCreate```
    * ```TrieSnapshotLength```
    * ```TrieSnapshotKeyBufferSize```
    * ```TrieSnapshotGetKey```
    * ```TrieSnapshotDestroy```
- Added new ```replace```parameters for ```TrieSet*``` natives to make operation fail if key already set.
- Added new ```size``` parameter for ```TrieGetString``` and **TrieGetArray``` to return the number of bytes written in the buffer.
- Updated documentation.
- Updated test plugin.