Use temp member to save new file

[worksofliam]

Changes

• Attempts to insert new file into temporary table first. This is good because we can check the file will be saved without clearing out the original member first.
• Seems to have seriously improved the performance of member saving

Checklist

• have tested my change
• updated relevant documentation
• Remove any/all console.logs I added
• eslint is not complaining
• have added myself to the contributors' list in CONTRIBUTING.md
• for feature PRs: PR only includes one feature enhancement.

[chrjorgensen]

Looking good and works perfectly!

[chrjorgensen]

I did not feel any speed improve - which would also not be logical, since two more steps is introduced to the save operation.
However, that was not the point either - the point being to have a safer save, not saving half a member. And the additional steps are almost not noticeable and a good compromise for the safer save.