[SIEM] Persist EventsViewer columns

[spong]

The Signals, Events, and External Alerts tables throughout the SIEM app provide the ability for users to customize the columns displayed, however this configuration is not persisted outside of redux, and so a hard refresh will result in the default columns being displayed instead of the user configured columns.

While Timelines currently support this functionality since they are backed by saved objects, the EventsViewer tables are not, and so will need to provide their own method of persisting the column configuration. For lightweight configuration like this we should be able to leverage local storage and the same logic that Timeline uses for serializing/loading the column settings.

The following configuration should be persisted:

• Selected columns
• Column order
• Column width
• Column sort (potentially?)

[elasticmachine]

Pinging @elastic/siem (Team:SIEM)

[spong]

Implemented as part of #67156, thanks @cnasikas! 🙂