Fix spelling errors

Most errors found with:

codespell -L cach,thst,odly,aslo,parm,parms,inpu,ges,prset,pevent,ptd,pring,valu,noo,noe,ned,inout,ro,siz,froms,nd,fo,singl,sart,multy,tthe,allong,ment,inate,nodel,tring,alse,ture,thi,wille,numer

Some more manually found (its -> it's)

c++20: Do not use apostrophe (e.g. can't) in unquoted #error message

modules/database/test/std/rec/asyncproctest.db

@@ -14,7 +14,7 @@ record(sub, "done1") {
 
 
 # original problem case
-# async record chained after syncronous record
+# async record chained after synchronous record
 record(calcout, "chain2:1") {
     field(CALC, "A:=A+1;B")
     # ODLY=0 synchronous

modules/database/test/std/rec/boTest.c

@@ -53,7 +53,7 @@ static void test_high(void){
     /* set VAL to process record */
     testdbPutFieldOk("test_bo_rec.VAL", DBF_SHORT, TRUE);
 
-    /* wait and verfiy time */
+    /* wait and verify time */
     testMonitorWait(test_mon);
     epicsTimeGetCurrent(&endTime);