Support for SiteWise externalId on asset search

[diehbria]

Is your feature request related to a problem? Please describe.

SiteWise released a feature to support the ability to provide an externalId to assets (https://docs.aws.amazon.com/iot-sitewise/latest/userguide/object-ids.html#external-ids).

Customers want to be able to select an asset based on externalId.

Currently in Grafana SiteWise, a user can select an asset based on an externalId, but the subsequent requests for timeseries data based on the asset selection fails as it attempts to utilize the externalId in the dataplane requests, a feature which is on the road map but not currently released.

The goal of this task is to make the changes necessary so that the dataplane requests for time-series data do not fail after selecting a asset based on externalId.

Below is the input where a user can enter in the externalId of an asset:

Describe the solution you'd like

It appears that currently grafana sitewise plugin utilizes the assetId the user enters into the input box as the asset id in the dataplane requests, causing the failure, since the dataplane does not support externalId yet. To resolve this task likely all that needs to occur is to utilize the assetId returned from the asset response, rather than the assetId entered into the text box.

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Customer experience:

User can input the externalId directly into the asset input box. There will be 3 scenarios:

1. user explicitly add the externalId: prefix, in which case the entered in string can be passed in directly to the request for the asset with no modification
2. user enters standard sitewise UUID as they would today (no modification, this behavior remains the same)
3. user enters in a string without the externalId: prefix, and the string does not match the SiteWise UUID pattern (basic regex check client side is fine). In this case the front-end automatically appends the externalId: prefix before making the network call.

Describe alternatives you've considered
N/A

Additional context
N/A