[UA] Check all spaces in getLogSourcesSettingDeprecationInfo

[afharo]

We noticed that getLogSourcesSettingDeprecationInfo only checks the configuration for the current space.

This can lead to users running Upgrade Assistant in one space, missing on deprecations occurring in other spaces.

The logic should make use of namespaces: ["*"] or namespaces: ['${spaceId}'] (while looping through all available spaces) to confirm that all spaces are compliant.

[elasticmachine]

Pinging @elastic/obs-ux-logs-team (Team:obs-ux-logs)

[rudolf]

@Kerry350 identified some challenges in getting this deprecation working across spaces: #189646 (comment)

Notably how to write UiSettings of different spaces.

Core exposes asScopedToClient which could allow for creating a UiSettingsClient for each space where a deprecation was detected https://github.com/elastic/kibana/blob/main/packages/core/ui-settings/core-ui-settings-server/src/contracts.ts#L83