Add query param to ListNamespacesRequest

[lorensr]

User requested feature

[yiminc]

What would the query looks like?

[lorensr]

My guess is just name substring would be good enough for most: { query: 'foo' } or { query: { name: 'foo' } } matching namespace named foobar, but could do fuzzy or add other fields

message NamespaceInfo {
    string name = 1;
    temporal.api.enums.v1.NamespaceState state = 2;
    string description = 3;
    string owner_email = 4;
    // A key-value map for any customized purpose.
    map<string, string> data = 5;
    string id = 6;