Improve go-ts-mode Imenu, navigation and electric pair (bug#60407)

Improve go-ts-mode Imenu, navigation and electric pair (bug#60407)

The Imenu items are extended to support "Method", "Struct",
"Interface", "Alias" and "Type".

go-ts-mode is updated to use the Imenu facility added in commit
b39dc7ab27a696a8607ab859aeff3c71509231f5.

Variable electric-indent-chars is set in order to improve integration
with Electric Pair mode.

* lisp/progmodes/go-ts-mode.el (go-ts-mode--imenu-1) (go-ts-mode--imenu):
Remove functions.
(go-ts-mode--defun-name, go-ts-mode--interface-node-p)
(go-ts-mode--struct-node-p, go-ts-mode--other-type-node-p)
(go-ts-mode--alias-node-p): New functions.
(go-ts-mode): Improve Imenu settings, navigation, add Electric Pair
mode settings.