chore(explore): Add header hints and update explore headers

[nsdeschenes]

Updates the headers for the Logs and Application Metrics pages to match the latest design-engineering patterns, adds tooltips/hints on Logs and Metrics, and refreshes the docs link on Traces.

Also moved the action buttons ("Add Metric" / "Add Equation" / "Save As") into the new page frame TopBar actions slot. Removing them from the page filter level, and rendering below the panels.

As well, fixed a padding and layout issue on the metrics page causing a slight inconsistency between it and other explore pages, in placement of the header elements.

Replaces #113314, which was opened on the previous branch name before the LOGS scope was folded in.

Closes EXP-881
Closes LOGS-714
Closes LOGS-715

Examples:

Tooltip	Example
Traces tooltip
Logs tooltip
Metrics tooltip

Metrics Page	Examples
Before with page-frame
After with page-frame
Before without page-frame
After without page-frame
Onboarding Project with page-frame

[linear-code]

EXP-881 Update Application Metrics and Traces page copy

LOGS-714 Top Bar Padding

LOGS-715 Update to be inline with new page layouts

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