[C++] Centralize Errors in ExecPlan

[asfimport]

See parent task - this removes the "finished" futures in exec plans and centralizes the error handling in ExecPlan so that an error just makes running tasks stop being scheduled.

Reporter: Sasha Krassovsky / @save-buffer
Assignee: Sasha Krassovsky / @save-buffer

PRs and other links:

• GitHub Pull Request #13848
• GitHub Pull Request #15253

_{Note: This issue was originally created as ARROW-17381. Please see the migration documentation for further details.}

[asfimport]

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