Add a nick field in the IRC server configuration form

fix #3317

Re-connect to postgresql when the connection is lost

fix #3336

Update the changelog with this latest feature

Don’t reflect an empty id if it was not included

Instead, generate a uuid for that message

Advertise the muc#stable_id feature on disco#info results

From XEP 0045:
“Note: the requirement to reflect the 'id' attribute was added in version
1.31 of this XEP. Servers following the new specification SHOULD advertise
that with a disco info feature of 'http://jabber.org/protocol/muc#stable_id'
on both the service domain and on individual MUCs, so that clients can check
for support.”

Reflect message IDs in channel MUCs

fix #3283

Add a multiline_message e2e test

Use a transaction around the DELETE + INSERT of the after_connection_commands

Otherwise we can imagine that two clients changing this value at the same
time would mix things up.

ref #3275

Add some missing include

Allow the execution of multiple commands after the IRC connection

fix #3275

Use Catch2’s single_include/ directory

Revert "C++17"

This reverts commit 3f088e7b3a1467a88e7c5ff9fb60dc4609d2bfa3.

Revert "Use std::optional<bool> instead of OptionalBool"

This reverts commit ba879a882e031d7b8503f78fe41d1210000c96ca.

Revert "Use if constexpr to make things a lot more readable"

This reverts commit d62ca9f87906be6f046fe9d07afb8bfb69c166e3.

Use if constexpr to make things a lot more readable

Use std::optional<bool> instead of OptionalBool

C++17

update docs to mention identd disable choice

follow coding style

optional identd