BUG/MINOR: peers: Missing TX cache entries reset.

BUG/MINOR: peers: Missing TX cache entries reset.

The TX part of a cache for a dictionary is made of an reserved array of ebtree nodes
which are pointers to dictionary entries. So when we flush the TX part of such a
cache, we must not only remove these nodes to dictionary entries from their ebtree.
We must also reset their values. Furthermore, the LRU key and the last lookup
result must also be reset.

(cherry picked from commit ea875e62e6b2f69c50533c5cd52eb5284c69723f)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 9650ee94b3cc5bc2e6c2a7cf67ef66c0273c1404)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit c65161466af0bbf1cce39727ffff1bbaefcfa9ec)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>