[LSP]: provide file type detection

[GitMensch]

Something like the following was suggestion by "AI" without further checks, so that has to be taken with a lot of salt...

documents.onDidChangeContent((change) => {
    const content = change.document.getText();

    // Detect GDB log content
    if (/\(gdb\)/.test(content) || /\#\d+\s+/.test(content)) {
        connection.sendNotification('customLanguageChange', { uri: document.uri, language: 'gdb-log' });
    }
    // Detect GDB commands
    else if (/\bdefine\b/.test(content) && /\bend\b/.test(content) || /\bbreak\b/.test(content)) {
        connection.sendNotification('customLanguageChange', { uri: document.uri, language: 'gdb' });
    }
});