runtime(vim): Update base syntax, improve :match highlighting

- Match the range prefix separately as a count.
- Match an explicit count of 1, rarely used but seen in the wild.
- Allow whitespace between the count and command.

closes: #17717

Signed-off-by: Doug Kearns <dougkearns@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/syntax/testdir/dumps/vim_ex_commands_20.dump

@@ -1,11 +1,9 @@
-|:+0&#ffffff0|o+0#af5f00255&|p|t|i|o|n|s| +0#0000000&@66
-|:|o+0#af5f00255&|u|n|m|a|p| +0#0000000&@67
-|:|o+0#af5f00255&|u|n|m|e|n|u| +0#0000000&@66
+|:+0&#ffffff0|o+0#af5f00255&|u|n|m|e|n|u| +0#0000000&@66
 |:|o+0#af5f00255&|w|n|s|y|n|t|a|x| +0#0000000&@64
 |:|p+0#af5f00255&|a|c|k|a|d@1| +0#0000000&@66
->:|p+0#af5f00255&|a|c|k|l|o|a|d|a|l@1| +0#0000000&@62
+|:|p+0#af5f00255&|a|c|k|l|o|a|d|a|l@1| +0#0000000&@62
 |:|p+0#af5f00255&|c|l|o|s|e| +0#0000000&@67
-|:|p+0#af5f00255&|e|d|i|t| +0#0000000&@68
+>:|p+0#af5f00255&|e|d|i|t| +0#0000000&@68
 |:|p+0#af5f00255&|e|r|l| +0#0000000&@69
 |:|p+0#af5f00255&|r|i|n|t| +0#0000000&@68
 |:|p+0#af5f00255&|r|o|f|d|e|l| +0#0000000&@66
@@ -17,4 +15,6 @@
 |:|p+0#af5f00255&|o|p|u|p| +0#0000000&@68
 |:|p+0#af5f00255&@1|o|p| +0#0000000&@69
 |:|p+0#af5f00255&|r|e|s|e|r|v|e| +0#0000000&@65
+|:|p+0#af5f00255&|r|e|v|i|o|u|s| +0#0000000&@65
+|:|p+0#af5f00255&|s|e|a|r|c|h| +0#0000000&@66
 @57|3|6|1|,|1| @8|2|9|%|