refactor: Rely on the newly introduced StaticFiles

This is one of the very interested features introduces by
deps: Update semantic-ui
fix: The Makefile now works for a fresh clone
refactor: Use the rocket_contrib newly introduced support for da

With rocket_contrib-0.4.0-rc.1, a new feature has been introduced in
order to easily share a database connection among route handler. It
was already easy before using managed state, but as it turned out, the
author decided to provide a standard implementation.

Once again, I really feel like it is a good call, and this allows for
removing code in ogmios which is great.
deps: rocket_codegen shall not be a direct dependency anymore

See the ChangeLog[¶] of rocket-0.4.0-rc.1 for more information about
this change. Considering all rocket project had to depend on it, I
would say it is a very good move.

deps: Update to rocket-0.4.0-rc.1 and latest ogmarkup

It was almost painless, even if the number of compiler error at first
was frightening. There were three kind of errors, due to breaking
changes in rocket.

  1. Typed-uri are great, but required Redirect::to calls to be fixed
  2. It looks like rocket is using its own internal Json
     implementation now

Besides, the galatian crate has been renamed ogmarkup, as its old
implementation in Haskell.
front: Install build products with makefile and cp rather than gulp
fix: It was not possible to validate a fresh sheet
refactor: Clean-up some warnings
front: Improve the look of future sheet buttons
refactor: Introduce helper functions to render ogmios templates

The previous situation was not acceptable, as many code was duplicated
across route handlers regarding the template generation. For instance,
each route has a call to retrieve the list of validated characters of
a given user.

Now, with shared::render_noauth_template, shared::render_auth_template
and shared::render_template, the situation is a bit better. We
probably will end up in situations where we are doing useless
requests, e.g. because we already fetched the list of characters. For
now, I consider this is OKay.
front: Improve the look of the list of characters
front: Introduce the so-called ogmios theme for Semantic-UI

For now, the only thing the ogmios theme is doing is using a different
font for the container element.
front: Correctly add Semantic-UI to this repo

Before running the website, you need to use the command `gulp build`.
feature: Improve navigation between current and future versions
chore: Update to latest galatian
fix: Update the raw text in addition to the rendered one
feature: Implement a complete validation process for characters
feature: Introduce character sheet and validation process

The present commit implements many changes related to character
information. Now, the main idea to keep in mind is that a given
character can have different versions of its information. The current
implementation lacks the actual validation.
front: Remove mini class in the characters' avatars display

Thanks to this change, they are more visible, because a bit larger.