Replace padding dots symbol by multiple dots (#16594)

Related to #16345.

Summary of the issue:
Multiple dots are reported as "padding dots" in situations where these dots have no padding function. "padding" is too restrictive and is also more difficult to understand; by the way, some translators have actually translated "padding dots" to "multiple dots" in their translations.

Description of user facing changes
Multiple dots (4 or more) will now be reported with the more neutral "multiple dots" instead of "padding dots" when the symbol level is high enough.

Description of development approach
Changed both the symbol name and what is reported in symbol file.

source/locale/en/symbols.dic

@@ -12,7 +12,7 @@ complexSymbols:
 ; phrase ending	(?<=[^\s;]);(?=\s|$)
 : phrase ending	(?<=[^\s:]):(?=\s|$)
 # Series of dots used for visual presentation, e.g. in table of contents
-padding .	\.{4,}
+multiple .	\.{4,}
 # Others
 decimal point	(?<![^\d -])\.(?=\d)
 in-word '	(?<=[^\W_])['’]
@@ -27,7 +27,7 @@ symbols:
 ? sentence ending	question	all	always
 ; phrase ending	semi	most	always
 : phrase ending	colon	most	always
-padding .	padding dots	all	always
+multiple .	multiple dots	all	always
 decimal point		none	always
 in-word '	tick	all	norep
 negative number	minus	none	norep