patch 8.2.0156: various typos in source files and tests

Problem:    Various typos in source files and tests.
Solution:   Fix the typos. (Emir Sari, closes #5532)
diff --git a/src/term.c b/src/term.c
index c74c5ba..1399286 100644
--- a/src/term.c
+++ b/src/term.c
@@ -146,7 +146,7 @@
 // Request cursor style report:
 static termrequest_T rcs_status = TERMREQUEST_INIT;
 
-// Request windos position report:
+// Request window's position report:
 static termrequest_T winpos_status = TERMREQUEST_INIT;
 
 static termrequest_T *all_termrequests[] = {