fix: Respect icon intent color passed to Dialog

[ggdouglas]

Fixes #6824

Checklist

• [N/A] Includes tests
• Update documentation

Changes proposed in this pull request:

Fixes an issue where dialog header would always overwrite the intent of an icon passed into the dialog, either though the icon prop:

<Dialog icon={<Icon icon={IconNames.INFO_SIGN} intent={Intent.PRIMARY} ... />}

or embedded in the title:

<Dialog title={<>Info <Icon icon={IconNames.INFO_SIGN} intent={Intent.PRIMARY} /></>} ... />}

Note: Icons with the color property set (e.g. <Icon icon={IconNames.INFO_SIGN} color={Colors.BLUE3} />) are not affected by this bug since they set color on the fill of the icon's SVG directly.

Screenshot

Light Mode

Before	After

Dark Mode

Before	After

[svc-palantir-github]

Add generated changelog entries

Build artifact links for this commit: documentation | landing | table | demo

This is an automated comment from the deploy-preview CircleCI job.

[svc-palantir-github]

Use qualified selector to omit icons with intent from coloring

Build artifact links for this commit: documentation | landing | table | demo

This is an automated comment from the deploy-preview CircleCI job.

[svc-palantir-github]

Remove unnecessary prefixed icon class

Build artifact links for this commit: documentation | landing | table | demo

This is an automated comment from the deploy-preview CircleCI job.

[svc-palantir-github]

Remove more duplicate nested classes

Build artifact links for this commit: documentation | landing | table | demo

This is an automated comment from the deploy-preview CircleCI job.