[Uptime] Remove tabs navigation in place of the new solution navigation

[formgeist]

Summary

Related to the new solution navigation

The new solution navigation will mean that the links which are displayed in the Uptime header as tabs will be available in the new side navigation. This means that the tabs will be redundant and should be removed.

Instead, we'll display the page title using the new EuiPageHeader component in conjunction with the EuiPage component.

[elasticmachine]

Pinging @elastic/uptime (Team:uptime)

[shahzad31]

blocked by #99380