[Searchable Snapshots] Prevent search node startup if there are more than a single data path

[kotwanikunal]

Is your feature request related to a problem? Please describe.

• For a search node, we will store the file cache as a part of the default data path defined by the user.
• To simplify the approach for search nodes, we should fail node startup if there are multiple data paths configured.

Describe the solution you'd like

• At node bootstrap, check if the node has search role and multiple data paths, if yes, fail the bootstrap.

Describe alternatives you've considered

• N/A

Additional context

• N/A

[dblock]

@kotwanikunal Link this back to a meta issue, alone it lacks context.

[kotwanikunal]

@kotwanikunal Link this back to a meta issue, alone it lacks context.

Thanks. Missed linking this one.