Fine-tune static network filtering engine code

Refactored heuristics to collate set of origin-related
filter units are collated into a hostname trie, and
for better reuse of existing classes.

Generalized pre-test idea for bucket of filters, such
that in addition to origin-related filter units, there is
now a class to collate regex-based pattern-related units
into a new pre-test bucket class, FilterBucketIfRegexHits,
in order to test with a single regex test whether there is
a chance of a hit in the underlying bucket of filters.
Instances of these are rare, but at time of commit I found
this occurs with AdGuard France filter list.

Fine-tuned the "SNFE: Dump" output -- this new ability to
see the internal details of the SNFE has been really key
into finding/fixing issues during refactoring.

src/js/background.js

@@ -174,8 +174,8 @@ const µBlock = {  // jshint ignore:line
 
     // Read-only
     systemSettings: {
-        compiledMagic: 43,  // Increase when compiled format changes
-        selfieMagic: 43,    // Increase when selfie format changes
+        compiledMagic: 44,  // Increase when compiled format changes
+        selfieMagic: 44,    // Increase when selfie format changes
     },
 
     // https://github.com/uBlockOrigin/uBlock-issues/issues/759#issuecomment-546654501