Modernized the plugin

Implemented fixes from Gitlab issues
from Marc Hagen & Trent Robinson (https://gitlab.com/jackgreyhat/librenms-speedtest/-/issues/2)
and fixes from m0nsieur Psych0 (https://gitlab.com/jackgreyhat/librenms-speedtest/-/issues/6)

I added support for darkmode, this is done by generating the graphs with white text, then using CSS to invert the image, for light mode users.

I also moved branding PNGs to vectors for higher resolutions

I will not be opening a PR at https://gitlab.com/jackgreyhat/librenms-speedtest as this seems to have been abbandoned.

install.sh

@@ -0,0 +1,25 @@
+# Install speedtest pkg
+sudo apt-get install curl
+sudo apt remove speedtest-cli
+curl -s https://packagecloud.io/install/repositories/ookla/speedtest-cli/script.deb.sh | sudo bash
+sudo apt-get install speedtest
+# Go to your home dir
+cd ~/
+# Clone this repository into your home dir
+git clone https://git.oldgate.org/Sophia/librenms-speedtest
+# Create the plugin directory into LibreNMS plugin folder
+mkdir /opt/librenms/html/plugins/Speedtest
+# Copy the LibreNMS speedtest plugin contents into the newly created directory
+cp -r ~/librenms-speedtest/. /opt/librenms/html/plugins/Speedtest
+# Ensure correct ownership and permissions on the Speedtest plugin directory and files
+chown -R librenms:librenms /opt/librenms/html/plugins/Speedtest
+chmod -R --reference=/opt/librenms/html/plugins /opt/librenms/html/plugins/Speedtest
+chmod +x /opt/librenms/html/plugins/Speedtest/librenms-speedtest.sh
+# Accept the speedtest EULA and GDPR notice (if applicable) and run an initial speedtest
+su -c 'speedtest --accept-license --accept-gdpr' librenms
+# Create the RRD files
+su -c 'bash /opt/librenms/html/plugins/Speedtest/librenms-speedtest.sh create' librenms
+# Test and run the speedtest script
+su -c 'bash /opt/librenms/html/plugins/Speedtest/librenms-speedtest.sh run' librenms
+# Output the speedtest results into PNG files
+su -c 'bash /opt/librenms/html/plugins/Speedtest/librenms-speedtest.sh graph' librenms