new grid: 'ch_cantons_grid3'

[AlexanderAriu]

An canton grid that...

[[Note: To help streamline the process of adding this grid, please replace this text with an image of a map for the region for reference. Also, please check the ISO_3166-2 (https://en.wikipedia.org/wiki/ISO_3166-2) codes if your grid uses countries or states/provinces. Finally, if you can provide an example of your grid in action with a data set and sample code, that would be great but is not required.]]

Grid data:

"code","name_local","name_de","name_fr","name_it","name_en","row","col"
"SH","Schaffhausen","Schaffhausen","Schaffhouse","Sciaffusa","Schaffhausen",2,6
"BS","Basel-Stadt","Basel-Stadt","Bâle-Ville","Basilea Città","Basel-City",2,4
"TG","Thurgau","Thurgau","Thurgovie","Turgovia","Thurgovia",3,7
"AG","Aargau","Aargau","Argovie","Argovia","Argovia",3,5
"JU","Jura","Jura","Jura","Jura","Jura",3,3
"BL","Basel-Landschaft","Basel-Landschaft","Bâle-Campagne","Basilea Campagna","Basel-Country",3,4
"ZH","Zürich","Zürich","Zurich","Zurigo","Zurich",3,6
"AI","Appenzell-Innerrhoden","Appenzell-Innerrhoden","Appenzell Rhodes-Intérieures","Appenzello Interno","Appenzell Inner-Rhodes",3,8
"NE","Neuchâtel","Neuenburg","Neuchâtel","Neuchâtel","Neuchâtel",4,3
"SO","Solothurn","Solothurn","Soleure","Soletta","Solothurn",4,4
"LU","Luzern","Luzern","Lucerne","Lucerna","Lucerne",4,5
"ZG","Zug","Zug","Zoug","Zugo","Zug",4,6
"SG","St.Gallen","St.Gallen","Saint-Gall","San Gallo","St.Gallen",4,7
"AR","Appenzell-Ausserrhoden","Appenzell-Ausserrhoden","Appenzell Rhodes-Extérieures","Appenzello Esterno","Appenzell Outer-Rhodes",4,8
"VD","Vaud","Waadt","Vaud","Vaud","Vaud",5,2
"FR","Fribourg","Freiburg","Fribourg","Friburgo","Fribourg",5,3
"BE","Bern","Bern","Berne","Berna","Bern",5,4
"NW","Nidwalden","Nidwalden","Nidwald","Nidvaldo","Nidwalden",5,5
"GE","Genève","Genf","Genève","Ginevra","Geneva",5,1
"SZ","Schwyz","Schwyz","Schwytz","Svitto","Schwyz",5,6
"GL","Glarus","Glarus","Glaris","Glarona","Glarus",5,7
"GR","Graubünden","Graubünden","Grisons","Grigioni","Grisons",5,9
"VS","Valais","Wallis","Valais","Vallese","Valais",6,3
"OW","Obwalden","Obwalden","Obwald","Obvaldo","Obwalden",6,5
"UR","Uri","Uri","Uri","Uri","Uri",6,6
"TI","Ticino","Tessin","Tessin","Ticino","Ticino",7,6