Renamed `inputDisabled` prop/variable in
`ThreadSettingsGeneralTab`, `ThreadSettingsPrivacyTab`,
`ThreadSettingsDeleteTab`, and `ThreadSettingsModal` to
`threadSettingsOperationInProgress`. This is because the `inputDisabled`
prop is determined by
1. Determining if there is a change in progress
2. Checking the current tab and determining if the current thread has
that tab's permissions
Thus, if `inputDisabled` is true, a thread settings operation is in
progress or the current thread does not have the current tab's
permissions. So `inputDisabled` is renamed to more accurately reflect the
cases in which it is true.