The jSignature lib is only used by the NameAndSignature component,
which is not accessible on a many screens. This commit thus
removes the lib and its extension from the bundles, and makes the
NameAndSignature component load it on demand.
Part of task~3439226
closesodoo/odoo#138054
Related: odoo/enterprise#48633
Signed-off-by: Samuel Degueldre (sad) <sad@odoo.com>
