* MM-35945: handle lots of files in ExtractTarGz
`ExtractTarGz` can fail on archives with a largish number or files, complaining about too many open file handles. Clean up as we go to avoid this.
Fixes: https://mattermost.atlassian.net/browse/MM-35945
* use closure to allow defer
* format using `goimports -local github.com/mattermost/mattermost-server/v5 -w`
* added goimports lint check to .golangci.yml
* format using `goimports -local github.com/mattermost/mattermost-server/v5 -w` for a corner case
* make app-layers, *-mocks and store-layers for ci check
Co-authored-by: Mahmudul Haque <mahmudulhaque@protonmail.com>
Co-authored-by: Mattermod <mattermod@users.noreply.github.com>
