Replace the outdated build_installer.sh with the steps used in CI,
call build_installer.sh from CI. Move the signing part into the new
script, sign_installer.sh.
Uninstaller is still unsigned, as currently building and signing in 'wine'
and running Linux osslsigncode inside Inno Setup inside wine is awkward.
Closes https://github.com/espressif/esp-idf/issues/1909
TW20810
These versions of conf/mconf are forked from the upstream, and the CMake system allows mconf-idf to
be installed externally on the path. So the best option is to rename.
Includes changes to Windows installer for v1.1
