feat: API: Add ValidateMnemonicWord and ValidateMnemonicPhrase (#204)

Resolves issue #203

* In gnonativeTypes.go, add request and response messages for
`ValidateMnemonicWord` and `ValidateMnemonicPhrase`
* In rpc.proto, add `ValidateMnemonicWord` and `ValidateMnemonicPhrase`
* Run `make regenerate`
* In gnoNativeService, implement `ValidateMnemonicWord` and
`ValidateMnemonicPhrase`
* In expo/src/api, update types.ts and GnoNativeApi.ts with
`validateMnemonicWord` and `validateMnemonicPhrase`

Tested in TypeScript if you have `word` and `phrase`:
```
const valid1 = await gnonative.validateMnemonicWord(word);
console.log('Word valid:', valid1);
const valid2 = await gnonative.validateMnemonicPhrase(phrase);
console.log('Phrase valid:', valid2);
```

Signed-off-by: Jeff Thompson <[email protected]>

Author: jefft0

api/gen/csharp/Gnonativetypes.cs

@@ -45,7 +45,7 @@ static RpcReflection() {
             "ARIZChRFcnJUb29NYW55U2lnbmF0dXJlcxDWARIUCg9FcnJOb1NpZ25hdHVy",
             "ZXMQ1wESEwoORXJyR2FzT3ZlcmZsb3cQ2AESFgoRRXJySW52YWxpZFBrZ1Bh",
             "dGgQ2QESEwoORXJySW52YWxpZFN0bXQQ2gESEwoORXJySW52YWxpZEV4cHIQ",
-            "2wEyyR0KEEdub05hdGl2ZVNlcnZpY2USXgoJU2V0UmVtb3RlEicubGFuZC5n",
+            "2wEy0h8KEEdub05hdGl2ZVNlcnZpY2USXgoJU2V0UmVtb3RlEicubGFuZC5n",
             "bm8uZ25vbmF0aXZlLnYxLlNldFJlbW90ZVJlcXVlc3QaKC5sYW5kLmduby5n",
             "bm9uYXRpdmUudjEuU2V0UmVtb3RlUmVzcG9uc2USXgoJR2V0UmVtb3RlEicu",
             "bGFuZC5nbm8uZ25vbmF0aXZlLnYxLkdldFJlbW90ZVJlcXVlc3QaKC5sYW5k",
@@ -125,12 +125,18 @@ static RpcReflection() {
             "aDMyUmVzcG9uc2USfAoTQWRkcmVzc0Zyb21NbmVtb25pYxIxLmxhbmQuZ25v",
             "Lmdub25hdGl2ZS52MS5BZGRyZXNzRnJvbU1uZW1vbmljUmVxdWVzdBoyLmxh",
             "bmQuZ25vLmdub25hdGl2ZS52MS5BZGRyZXNzRnJvbU1uZW1vbmljUmVzcG9u",
-            "c2USUgoFSGVsbG8SIy5sYW5kLmduby5nbm9uYXRpdmUudjEuSGVsbG9SZXF1",
-            "ZXN0GiQubGFuZC5nbm8uZ25vbmF0aXZlLnYxLkhlbGxvUmVzcG9uc2USZgoL",
-            "SGVsbG9TdHJlYW0SKS5sYW5kLmduby5nbm9uYXRpdmUudjEuSGVsbG9TdHJl",
-            "YW1SZXF1ZXN0GioubGFuZC5nbm8uZ25vbmF0aXZlLnYxLkhlbGxvU3RyZWFt",
-            "UmVzcG9uc2UwAUIvWidnaXRodWIuY29tL2dub2xhbmcvZ25vbmF0aXZlL2Fw",
-            "aS9nZW4vZ2+iAgNSVEdiBnByb3RvMw=="));
+            "c2USfwoUVmFsaWRhdGVNbmVtb25pY1dvcmQSMi5sYW5kLmduby5nbm9uYXRp",
+            "dmUudjEuVmFsaWRhdGVNbmVtb25pY1dvcmRSZXF1ZXN0GjMubGFuZC5nbm8u",
+            "Z25vbmF0aXZlLnYxLlZhbGlkYXRlTW5lbW9uaWNXb3JkUmVzcG9uc2UShQEK",
+            "FlZhbGlkYXRlTW5lbW9uaWNQaHJhc2USNC5sYW5kLmduby5nbm9uYXRpdmUu",
+            "djEuVmFsaWRhdGVNbmVtb25pY1BocmFzZVJlcXVlc3QaNS5sYW5kLmduby5n",
+            "bm9uYXRpdmUudjEuVmFsaWRhdGVNbmVtb25pY1BocmFzZVJlc3BvbnNlElIK",
+            "BUhlbGxvEiMubGFuZC5nbm8uZ25vbmF0aXZlLnYxLkhlbGxvUmVxdWVzdBok",
+            "LmxhbmQuZ25vLmdub25hdGl2ZS52MS5IZWxsb1Jlc3BvbnNlEmYKC0hlbGxv",
+            "U3RyZWFtEikubGFuZC5nbm8uZ25vbmF0aXZlLnYxLkhlbGxvU3RyZWFtUmVx",
+            "dWVzdBoqLmxhbmQuZ25vLmdub25hdGl2ZS52MS5IZWxsb1N0cmVhbVJlc3Bv",
+            "bnNlMAFCL1onZ2l0aHViLmNvbS9nbm9sYW5nL2dub25hdGl2ZS9hcGkvZ2Vu",
+            "L2dvogIDUlRHYgZwcm90bzM="));
       descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
           new pbr::FileDescriptor[] { global::Land.Gno.Gnonative.V1.GnonativetypesReflection.Descriptor, },
           new pbr::GeneratedClrTypeInfo(new[] {typeof(global::Land.Gno.Gnonative.V1.ErrCode), }, null, new pbr::GeneratedClrTypeInfo[] {