API v4 migration - updates (DO NOT MERGE)

[dfberry]

Fixes #396, #386, #350

Changes

1. infra: secrets for cosmosdb, postgresdb, and appinsights are in keyvault
2. scripts: key vault secrets read into env for db restore
3. packages: api -> api-legacy (v3 programming model)
4. packages: api-v4 -> api (v4 programming model)
5. packages/api/src: @azure/identity -> v4.0.0
6. packages/api/src/index.ts: function names: remove duplicate and rename for function-verb
7. packages/api/src/config/index: use appInsights

Verify changes requires the following:

1. do not deploy stripe package - this is unrelated to changes in this PR but does fail the deployment so comment out the stripe service in azure.yml before deploying
2. SWA ssl error - still unclear what that is - but I worked it around it by changing the URL to http then continuing past the warning, then it redirects to the correct SWA + data returned from Fns - it looked it @manekinekko might be looking into this

https://green-field-052295603.4.azurestaticapps.net/home

@glaucia86 - fyi

@manekinekko @anfibiacreativa Ready for review.

[glaucia86]

Thanks, @dfberry!

p.s.: just for your information, @dfberry and I made code review together this PR last Friday (11/10), once is related with the v3 to v4 migration PR

[manekinekko]

I've got a few issues when:

1. after logged in successfully, I was redirected to /home with a blank screen
2. when I clicked on a favorite button, I got a 500 error on the API call
3. when I clicked on the reserve button I got the pop alerte
   

[dfberry]

Working with @jongio and @glaucia86 for infra corrections.

[diberry]

Closing - the infra updates need to be separated from the API v4.