You have a \pagestyle{empty} instruction that does precisely that: it removes anything from page headers and footers.
The default for the report class is \pagestyle{plain}, which simply adds the page number at the center of the footer and is always used in the starting chapter pages.
So the solution is to remove \pagestyle{empty}.
If you don't want any page number in the front matter, then using \pagestyle{empty} is not sufficient, as every \chapter command will use \pagestyle{plain} in the page where the chapter title is, including the table of contents and the list of figures or tables.
I'm not keen to not having page numbers in the front matter, other than in a dedication page. However, this is solvable.
I'll use a reduced preamble just to show what you can do; add the packages you need.
\documentclass[a4paper,12pt]{report}
%<insert here the packages you need>
\makeatletter
\let\latexps@plain\ps@plain
\newcommand{\frontmatter}{\let\ps@plain\ps@empty\pagestyle{empty}}
\newcommand{\mainmatter}{%
\let\ps@plain\latexps@plain\pagestyle{plain}%
\clearpage
\pagenumbering{arabic}}
\makeatother
\begin{document}
\frontmatter
\input{title-content}
\clearpage
\input{dedicaces-content}
\clearpage
\input{remerciement-content}
\clearpage
\doublespacing
\tableofcontents
\listoftables
\listoffigures
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\mainmatter
\chapter{Introduction générale}
In this way all pages in the front matter won't have any number; the numbering will start at 1 for the first chapter.
Unrelated, but important: add \clearpage before \pagenumbering{arabic}, because this command doesn't start a new page. I'd use \input rather than \include for the front matter material (adding \clearpage when a page break is wanted).
{}(curly braces) icon above the edit window, just as I did.:)If you have inline code, this link could be useful: How do I mark inline code? – Count Zero Oct 30 '12 at 21:10\pagestyle{empty}, so you're telling LaTeX to remove the page numbers; however, in starting chapter pages, the page style LaTeX uses isplain. Remove\pagestyle{empty}. – egreg Oct 30 '12 at 21:11