vim: Increment search right (#10866)

Hi there, nice editor!
Here's my attempt at fixing #10865.

Thanks

Release Notes:

-vim: Fix ctrl+a when cursor is on a decimal point
([#10865](https://github.com/zed-industries/zed/issues/10865)).

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Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>

crates/vim/test_data/test_increment_with_dot.json

@@ -0,0 +1,5 @@
+{"Put":{"state":"1ˇ.2\n"}}
+{"Key":"ctrl-a"}
+{"Get":{"state":"1.ˇ3\n","mode":"Normal"}}
+{"Key":"ctrl-x"}
+{"Get":{"state":"1.ˇ2\n","mode":"Normal"}}

crates/vim/test_data/test_increment_with_two_dots.json

@@ -0,0 +1,5 @@
+{"Put":{"state":"111.ˇ.2\n"}}
+{"Key":"ctrl-a"}
+{"Get":{"state":"111..ˇ3\n","mode":"Normal"}}
+{"Key":"ctrl-x"}
+{"Get":{"state":"111..ˇ2\n","mode":"Normal"}}