Review electron app menu

[bloodearnest]

We currently have the default electron app menu

There's lots of things there, and we may want to remove some: e.g. "Developer Tools"

We also may want to custom existing ones or add new ones.

Some ideas that have been discussed

• view logs
• open different json file
• show version/build information
• detailed About dialog with links

[lucyb]

A customised About dialog, with the version information was added in this ticket https://github.com/opensafely-core/sacro/issues/132

Making the build date visible is covered in this ticket https://github.com/opensafely-core/sacro/issues/132

Opening a different file is covered in this PR https://github.com/opensafely-core/sacro/pull/144

[madwort]

covered in other tickets