### [REF] account_reports: conversion to owl

This commit converts account_reports to owl.

Here is a list of the main components:

* **AccountReportController** is the main component. It is in charge of
all the heavy lifting like getting the data from the database (with
get_report_information), keeping the data well formatted with
getters/setters functions, offering a bunch of helpers functions and
managing functions useful for other components (line visibility,
footnotes, etc).

* **AccountReport** represent an account report (duh). Its main function is
to construct the report. It is the one that calls
AccountReportController to get the data and make it available on other
components. It is also in charge of the overriding of components and
templates that allows reports to be fully customizable. To override a
component you can use the `_get_custom_display_config` hook function defined in
`account_reports.py`.

* **AccountReportFilters** is in charge of managing all the filters
available on an account report.

* **AccountReportHeader** is the table header of a report. It can manage
all column interactions such as sorting.

* **AccountReportLine** represents a table row of a report (expect the ones
on the table header). It also manage the debug popover.

* **AccountReportLineName** represents the cell on the far left of a table row.
It manages the load more, the caret options and the foldable of a line.

* **AccountReportLineCell** represents all other cells of a table row. It is
in charge of the auditable functionality and the edition of manual
values.

As said, those are only the main components. There is a few more used
for more specific stuff.

This commit also separates the templates used for the display of account
reports in the web client and the templates used for pdf printing. The
pdf templates can be overriden the same way as the components by using
the `_get_custom_display_config` hook function on `account_reports.py`.