Revert "slaprunner: fix resiliency test, add development-mode (bool) parameter for easy build webrunner in webrunner"

This reverts commit 59966611.

hosts-dict values cannot be domain names.
memcached entries are implementation-independent (no mention of kumofs
anymore).
relational database information (which does not follow above memcached
rule, sadly, naming mariadb explicitly) is published in two lists.
Add minimal patterns to document what requester should expect.
Document deadlock-debugger-password".
Drop non-standard "optional" property from jupyter-url declaration.

slaprunner: fix resiliency test, add development-mode (bool) parameter for easy build webrunner in webrunner

This is backported to ZODB-3.10 https://github.com/zopefoundation/persistent/pull/44

The patch is needed for wendelin.core to being able to relase not needed
memory.

/reviewed-on nexedi/slapos!93