MINOR: checks: Add option to tcp-check expect rules to customize error status

MINOR: checks: Add option to tcp-check expect rules to customize error status

It is now possible to specified the healthcheck status to use on error or on
timeout for tcp-check expect rules. First, to define the error status, the
option "error-status" must be used followed by "L4CON", "L6RSP", "L7RSP" or
"L7STS". Then, to define the timeout status, the option "tout-status" must be
used followed by "L4TOUT", "L6TOUT" or "L7TOUT".

These options will be used to convert specific protocol healthchecks (redis,
pgsql...) to tcp-check ones.
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