Use top-level await once esbuild supports it

[coderbyheart]

evanw/esbuild#253

Use it in places, where we fetch lambda settings from SSM:

asset-tracker-cloud-aws-js/third-party/nrfcloud.com/agps.ts

Line 19 in 801dbab

const settingsPromise = getAGPSLocationApiSettings({

asset-tracker-cloud-aws-js/third-party/nrfcloud.com/ncellmeasgeolocation.ts

Line 14 in 801dbab

const settingsPromise = getCellLocationApiSettings({

asset-tracker-cloud-aws-js/third-party/nrfcloud.com/pgps.ts

Line 19 in 801dbab

const settingsPromise = getPGPSLocationApiSettings({

asset-tracker-cloud-aws-js/third-party/unwiredlabs.com/cellgeolocation.ts

Line 12 in 801dbab

const settingsPromise = getApiSettings({