Deprecate 'c', 'C' prefix for octal literals, fixes #8082 (#8178)

* deprecate `0c`, `0C` prefix for octal literals

Deprecates the previously allowed syntax of `0c` and `0C` as a prefix for
octal literals to bring the literals in line with the behavior of
`parseOct` from parseutils.

* add `msgKind` arg to `lexMessageLitNum` for deprecation messages

* change literal tests to check all valid integer literals

Also adds the `tinvaligintegerlit3` test to test for the (still)
invalid `0O` prefix.

tests/lexer/tintegerliterals.nim

@@ -0,0 +1,9 @@
+# test the valid literals
+assert 0b10 == 2
+assert 0B10 == 2
+assert 0x10 == 16
+assert 0X10 == 16
+assert 0o10 == 8
+# the following is deprecated:
+assert 0c10 == 8
+assert 0C10 == 8

tests/lexer/tinvalidintegerliteral3.nim

@@ -0,0 +1,7 @@
+discard """
+  file: "tinvalidintegerliteral3.nim"
+  line: 7
+  errormsg: "0O5 is an invalid int literal; For octal literals use the '0o' prefix."
+"""
+
+echo 0O5