Improve Bool parsing and add sequence serialization

[MarcAntoine-Arnaud]

No description provided.

[oli-obk]

Sorry, we won't support this. Use serde(deserialize_with) instead. Reasoning: #18 (comment)

[farodin91]

Also dublicated sequence serialization see #36

[MarcAntoine-Arnaud]

Regarding Boolean, the W3C standard mention ·boolean· can have the following legal literals {true, false, 1, 0}.
This is why it can made sense to add it in this library.

[oli-obk]

@RReverser opinions?

[RReverser]

3.2.2.1 Lexical representation
An instance of a datatype that is defined as ·boolean· can have the
following legal literals {true, false, 1, 0}.

3.2.2.2 Canonical representation
The canonical representation for boolean is the set of
literals {true, false}.

This is interesting indeed. If that's called a canonical representation by spec, I agree it's a game changer and makes sense to support it by default (assuming we are still able to have helper functions for 0 / 1 and "exists" / "doesn't exist" representations).

[RReverser]

@MarcAntoine-Arnaud Could you please split your commits into two PRs so that we don't mix discussions?