[solarwatt] Initial contribution for solarwatt energy manager (#10091)

* [ADD] First version which was tested with my local setup.

Signed-off-by: Sven Carstens <s.carstens@gmx.de>
Signed-off-by: Sven Carstens <sven.carstens@aoe.com>

* [ADD] Refactoring, add calculated value for direct self consumption and prepare for more.

Signed-off-by: Sven Carstens <s.carstens@gmx.de>

* [ADD] Add chanel description to README and make some channels advanced.

Signed-off-by: Sven Carstens <s.carstens@gmx.de>

* [MOD] Remove wrong colon in channel types.

Signed-off-by: Sven Carstens <s.carstens@gmx.de>

* [MOD] Put colon at the right place in channel types.

Signed-off-by: Sven Carstens <s.carstens@gmx.de>

* [MOD] Fix spelling of PVPlant in constants and things.

Signed-off-by: Sven Carstens <s.carstens@gmx.de>

* [MOD] Separate channelName from energy manager tagName.

Signed-off-by: Sven Carstens <s.carstens@gmx.de>

* [MOD] Reduce loglevels and fix findings from code-analysis.

Signed-off-by: Sven Carstens <s.carstens@gmx.de>

* [MOD] Move all custom calculations to the handler instances, remove custom tracking of child handlers, fix wrong calculation of the "direct consumed" values.

Signed-off-by: Sven Carstens <s.carstens@gmx.de>

* [MOD] Improve README and remove unnecessary Nullable and NotNull annotations.

Signed-off-by: Sven Carstens <s.carstens@gmx.de>

* [MOD] Change wrong ItemType for power items in README

Signed-off-by: Sven Carstens <s.carstens@gmx.de>

* [MOD] Change modeConverter to Switch

Signed-off-by: Sven Carstens <s.carstens@gmx.de>

* [MOD] Relay stateDevice to Thing status, anything but "OK" means ThingStatus.OFFLINE

Signed-off-by: Sven Carstens <s.carstens@gmx.de>

* [MOD] Remove stateDevice from items as it is represented by the device status.

Signed-off-by: Sven Carstens <s.carstens@gmx.de>

* [MOD] Improve README and remove unnecessary logging.

Signed-off-by: Sven Carstens <s.carstens@gmx.de>

* [MOD] Improve README.

Signed-off-by: Sven Carstens <s.carstens@gmx.de>

* [MOD] Improve README.

Signed-off-by: Sven Carstens <s.carstens@gmx.de>

* [MOD] Allow child things to be configured by hand with a guid.

Signed-off-by: Sven Carstens <s.carstens@gmx.de>

* [MOD] Allow child things to be configured by hand with a guid.

Signed-off-by: Sven Carstens <s.carstens@gmx.de>

* [MOD] Improve README and move things config to separate config.xml

Signed-off-by: Sven Carstens <s.carstens@gmx.de>

* [MOD] Improve README and remove all trace/debug logging.

Signed-off-by: Sven Carstens <s.carstens@gmx.de>

* [MOD] Use real channel timestamp as the refresh trigger.

Signed-off-by: Sven Carstens <s.carstens@gmx.de>

Co-authored-by: Sven Carstens <sven.carstens@aoe.com>

CODEOWNERS

@@ -271,6 +271,7 @@
 /bundles/org.openhab.binding.snmp/ @openhab/add-ons-maintainers
 /bundles/org.openhab.binding.solaredge/ @alexf2015
 /bundles/org.openhab.binding.solarlog/ @johannrichard
+/bundles/org.openhab.binding.solarwatt/ @sven-carstens
 /bundles/org.openhab.binding.somfymylink/ @loungeflyz
 /bundles/org.openhab.binding.somfytahoma/ @octa22
 /bundles/org.openhab.binding.sonos/ @kgoderis @lolodomo