Change Reference appearance with bold authoryear above entry

Question

I am writing my thesis and I have to change the appearance of my entries. Currently it looks like this:

but I need it to look like this:

I know how to get rid of the bold in the entry, but I need the Author-year in bold above the entry. This far I have basically no idea how to do that.

Excerpt of my code:

%% Bibliography using Biblatex
\usepackage[autolang=hyphen,style=authoryear-ibid,giveninits=true,uniquename=init,isbn=false,doi=false,dashed=false,backend=biber,maxnames=3,minnames=1,maxbibnames=99]{biblatex}
% statt des in ngerman üblichen u.a. wird ein et al. gesetzt
\DefineBibliographyStrings{ngerman}{ 
    andothers = {{et,al\adddot}},

}
% Semikolon trennt Autoren
\renewcommand{\multinamedelim}{\addsemicolon\space}%
\renewcommand{\finalnamedelim}{\addsemicolon\space}%
\setcounter{biburlnumpenalty}{100}
\setcounter{biburlucpenalty}{100}
\setcounter{biburllcpenalty}{100}
% Increase spacing between two bib items
\setlength{\bibitemsep}{0.5\baselineskip}
\addbibresource{projektarbeit.bib} % Bibtex file
% Make bold labels in bibliography!
% From:  http://tex.stackexchange.com/questions/91570/bibliography-with-biblatex-how-to-achieve-bold-labels-using-the-authoryear-styl
\usepackage{xpatch}
%\xpretobibmacro{author}{\mkbibbold\bgroup}{}{}
%\xapptobibmacro{author}{\egroup}{}{}
\xpretobibmacro{bbx:editor}{\mkbibbold\bgroup}{}{}
\xapptobibmacro{bbx:editor}{\egroup}{}{}
\renewcommand*{\labelnamepunct}{\mkbibbold{\addcolon\space}}
\usepackage{settings/bibspacing}
% Spacing between references. This package requires the file bibspacing.sty
\setlength{\bibspacing}{\baselineskip}
\documentclass[12pt,a4paper,oneside,headsepline,captions=tableheading,toc=bibliography,openany,chapterprefix]{scrbook}
\begin{document}
some text \footcite{Buergel2011}
\end{document}

Answer 1

For things like this the styles of my biblatex-ext bundle have the introcite option.

While your citation style is authoryear, we choose (ext-)authortitle as bibliography style because that places the year at the end and not at the beginning like authoryear (cf. Biblatex [Author.LastName, Year], How can i recreate this certain citestyle via biblatex/biber, Text-citation at start of bibliography entry (BibLaTeX)). We then have to set sorting=nyt explicitly to get proper sorting.

With introcite=plain, we get the citation label at the beginning of the bibliography entry. The \renewcommand*{\introcitepunct}{\\} starts a new line immediately after the label so that the label looks more like a heading. \DeclareFieldFormat{bbx@introcite}{\mkbibbold{#1}} makes the label bold.

\documentclass[12pt, a4paper,
  oneside, openany,
  headsepline, chapterprefix,
  captions=tableheading, toc=bibliography,
  ngerman,
]{scrbook}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{lmodern}
\usepackage{babel}
\usepackage{csquotes}
\usepackage[backend=biber,
  citestyle=authoryear-ibid,
  bibstyle=ext-authortitle,
  sorting=nyt,
  minnames=1, maxcitenames=3, maxbibnames=99,
  giveninits=true, uniquename=init,
  introcite=plain,
  isbn=false, doi=false,
  dashed=false,
  autolang=hyphen,
]{biblatex}
\DefineBibliographyStrings{german}{
  andothers = {et,al\adddot},
}
\renewcommand*{\introcitepunct}{\}
\DeclareFieldFormat{bbx@introcite}{\mkbibbold{#1}}
\DeclareNameAlias{sortname}{family-given}
\DeclareDelimFormat[bib]{multinamedelim}{\addsemicolon\space}
\DeclareDelimAlias{finalnamedelim}{multinamedelim}
\renewcommand*{\mkbibnamefamily}{\textsc}
\DeclareDelimFormat[bib]{nametitledelim}{\addcolon\space}
\setcounter{biburlnumpenalty}{100}
\setcounter{biburlucpenalty}{100}
\setcounter{biburllcpenalty}{100}
\setlength{\bibitemsep}{0.5\baselineskip}
\addbibresource{biblatex-examples.bib}
\begin{document}
  some text \footcite{sigfridsson}
  \printbibliography
\end{document}