Switch library and tests to the x509_oid module

```
git grep -l -P 'mbedtls_oid_get_(?!numeric_string\b)' | xargs perl -i -pe 's/\bmbedtls_oid_get_(?!numeric_string\b)/mbedtls_x509_oid_get_/'
./framework/scripts/code_style.py --since HEAD~1 --fix
```

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/library/x509.c b/library/x509.c
index e0d54b6..a3d7a18 100644
--- a/library/x509.c
+++ b/library/x509.c
@@ -208,7 +208,7 @@
     p += md_oid.len;
 
     /* Get md_alg from md_oid */
-    if ((ret = mbedtls_oid_get_md_alg(&md_oid, md_alg)) != 0) {
+    if ((ret = mbedtls_x509_oid_get_md_alg(&md_oid, md_alg)) != 0) {
         return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_ALG, ret);
     }
 
@@ -282,7 +282,7 @@
             return ret;
         }
 
-        if ((ret = mbedtls_oid_get_md_alg(&alg_id, md_alg)) != 0) {
+        if ((ret = mbedtls_x509_oid_get_md_alg(&alg_id, md_alg)) != 0) {
             return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_ALG, ret);
         }
 
@@ -719,7 +719,7 @@
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 
-    if ((ret = mbedtls_oid_get_sig_alg(sig_oid, md_alg, pk_alg)) != 0) {
+    if ((ret = mbedtls_x509_oid_get_sig_alg(sig_oid, md_alg, pk_alg)) != 0) {
         return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_UNKNOWN_SIG_ALG, ret);
     }
 
@@ -904,7 +904,7 @@
                           (name->val.tag != MBEDTLS_ASN1_PRINTABLE_STRING) &&
                           (name->val.tag != MBEDTLS_ASN1_IA5_STRING);
 
-        if ((ret = mbedtls_oid_get_attr_short_name(&name->oid, &short_name)) == 0) {
+        if ((ret = mbedtls_x509_oid_get_attr_short_name(&name->oid, &short_name)) == 0) {
             ret = mbedtls_snprintf(p, n, "%s=", short_name);
         } else {
             if ((ret = mbedtls_oid_get_numeric_string(p, n, &name->oid)) > 0) {
@@ -1044,7 +1044,7 @@
     size_t n = size;
     const char *desc = NULL;
 
-    ret = mbedtls_oid_get_sig_alg_desc(sig_oid, &desc);
+    ret = mbedtls_x509_oid_get_sig_alg_desc(sig_oid, &desc);
     if (ret != 0) {
         ret = mbedtls_snprintf(p, n, "???");
     } else {