Warnings in pool creation wizard

New pool creation wizard is supposed to show warnings in multiple places:

1. Within manual selection dialog.

2. Within some steps when form is incorrect or results in incorrect configuration.

3. On review step (let’s add a new wide section called warnings and list warnings from all previous steps).

Warnings should be shown in different colors based on their severity.
See old pool creation for some warnings.

Examples of warnings:

• Name not added.

• At least 1 data vdev is required.

• A stripe {vdevType} vdev is highly discouraged and will result in data loss if it fails. (Red - see getStripeVdevTypeErrorMsg)

• A stripe log vdev may result in data loss if it fails combined with a power outage. (Orange - see getLogVdevTypeWarningMsg)

• When user decided to use one of the disks with non-serial numbers (see first step), we should repeat warning on the review step: “Disks {disks} have non-unique serial numbers…” (Orange - see first step and nonUniqueSerialDisksWarning).

• Same for when disks with exported pools are used.

TODO:

• Add warnings to review step.

• Add warnings to appropriate places on their steps and in manual selection dialog.
  Generally the idea is that we want to communicate warning first in the place where it occurs and then on review step.

• It may be better to come up with some sort of service that would generate those warnings, so that they are in one place.

• Add tests.