When pressing delete on "[a] b c" the result is " b c" instead of
" b c". As result, text is rendered as "[]b c". The cause lies in
`deleteRange`: it ensures trailing spaces remains visible, but does not
take care of eventual invisible leading spaces. This adapts it to make
use of `prepareUpdate` which is made to handle this sort of issues. In
so doing we need to adapt `getState` and `prepareUpdate` to handle the
special cases brought by `deleteRange`. An option is introduced in
`prepareUpdate` to prevent its reentry until the update is complete (as
otherwise we may restore invalid intermediary states in the middle of
the deletion process).
task-3143042
X-original-commit: 8fd69afa591d11afe07da803ec550f052402713f
Part-of: odoo/odoo#138549
Antoine Guenet
0c95529e0f