fix: resolve all ESLint linting errors

- lib/ParseError.ts: Add public constructor modifier, fix type assertion syntax
- lib/RdfXmlParser.ts:
  - Fix NCNAME_MATCHER regex (misleading char class, long line) using RegExp constructor
  - Add public/return type annotations throughout (constructor, _transform, validateNcname, attachSaxListeners, onTag, onTagResource, onTagProperty, emitTriple, claimNodeId, onText, onCloseTag, onDoctype, setDirection, setVersion)
  - Fix unsafe type assertions using angle-bracket syntax
  - Fix SaxesParser field type to SaxesParser<{ xmlns: true }> for type safety
  - Fix no-fallthrough in switch statement with 'Falls through' comment
  - Fix capitalized-comments violations
  - Refactor createLiteral to avoid indentation/ternary issues
  - Format all emitTriple/push calls with consistent multi-line argument style
  - Fix onDoctype regex: add u flag, use replaceAll, type callback params
  - Fix validateUri defaulting to true when not specified
  - Add es2021.string to tsconfig lib arrays for replaceAll support
- test/RdfXmlParser-test.ts:
  - Replace all return expect(...) with await expect(...)
  - Make non-async callbacks async
  - Fix duplicate test title
  - Fix toThrow() missing message
  - Add eslint-disable-next-line for unavoidably long test title

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Co-authored-by: rubensworks <440384+rubensworks@users.noreply.github.com>

Author: Copilot

lib/ParseError.ts

@@ -5,8 +5,8 @@ import type { RdfXmlParser } from './RdfXmlParser';
  * An error that includes line and column in the error message.
  */
 export class ParseError extends Error {
-  constructor(parser: RdfXmlParser, message: string) {
-    const saxParser: SaxesParser = (<any>parser).saxParser;
+  public constructor(parser: RdfXmlParser, message: string) {
+    const saxParser: SaxesParser = (<{ saxParser: SaxesParser }><unknown>parser).saxParser;
     super(parser.trackPosition ? `Line ${saxParser.line} column ${saxParser.column + 1}: ${message}` : message);
   }
 }