unshelve: store information about interactive mode in shelvedstate
This is a follow-up patch to 5162753c4c14. This makes `unshelve`
stores the information about interactive mode on conflicts.
Differential Revision: https://phab.mercurial-scm.org/D6679
# See http://EditorConfig.org for the specification
root = true
[*.py]
indent_size = 4
indent_style = space
trim_trailing_whitespace = true
[*.{c,h}]
indent_size = 8
indent_style = tab
trim_trailing_whitespace = true
[*.t]
indent_size = 2
indent_style = space
trim_trailing_whitespace = false