Add tengo support to RemoteNickFormat (#793)

This commit add support for using the result of a tengo script in RemoteNickFormat using {TENGO}
Also adds a new toml table [tengo] with key RemoteNickFormat and value location of the script.
This also moves the TengoModifyMessage from [general] to Message in [tengo]

Documentation:

RemoteNickFormat allows you to specify the location of a tengo (https://github.com/d5/tengo/) script.
The script will have the following global variables:
to modify: result
to read: channel, bridge, gateway, protocol, nick

The result will be set in {TENGO} in the RemoteNickFormat key of every bridge where {TENGO} is specified
The script is reloaded on every message, so you can modify the script on the fly.
Example script can be found in https://github.com/42wim/matterbridge/tree/master/contrib/remotenickformat.tengo

[tengo]
RemoteNickFormat="remotenickformat.tengo"

1 files changed, 9 insertions, 0 deletions

diff --git a/contrib/remotenickformat.tengo b/contrib/remotenickformat.tengo
new file mode 100644
index 00000000..2ca856eb
--- /dev/null
+++ b/contrib/remotenickformat.tengo
@@ -0,0 +1,9 @@
+/*
+This script will return the current time in kitchen format if the protocol (of the remote bridge) isn't irc
+See https://github.com/d5/tengo/blob/master/docs/stdlib-times.md
+This result can be used in {TENGO} in RemoteNickFormat
+*/
+times := import("times")
+if protocol != "irc" {
+   result=times.time_format(times.now(),times.format_kitchen)
+}