Enhance security information retrieval and handling (#1826)

* Enhance security information retrieval and handling

- Add support for operating MIC codes in security info fetching
- Update security uniqueness validation to handle unknown securities
- Improve security creation and update logic in Plaid investment sync
- Update combobox and view components to handle operating MIC codes
- Add unknown flag for securities with incomplete information

* Update schema.rb

* Refactor the need for mic codes

* Don't fetch prices unless a security has the necessary mic code

* Deduplication

* Lint

* Update Securities and Plaid Investment Sync

- Modify PlaidInvestmentSync to return plaid_security for USD cash
- Add non-null constraint to Securities ticker column
- Update Securities fixture to use exchange_operating_mic instead of exchange_mic

---------

Signed-off-by: Josh Pigford <josh@joshpigford.com>

app/models/security.rb

@@ -6,7 +6,7 @@ class Security < ApplicationRecord
   has_many :prices, dependent: :destroy
 
   validates :ticker, presence: true
-  validates :ticker, uniqueness: { scope: :exchange_mic, case_sensitive: false }
+  validates :ticker, uniqueness: { scope: :exchange_operating_mic, case_sensitive: false }
 
   class << self
     def search(query)
@@ -30,11 +30,15 @@ class Security < ApplicationRecord
       name: name,
       logo_url: logo_url,
       exchange_acronym: exchange_acronym,
-      exchange_mic: exchange_mic,
+      exchange_operating_mic: exchange_operating_mic,
       exchange_country_code: country_code
     )
   end
 
+  def has_prices?
+    exchange_operating_mic.present?
+  end
+
   private
 
     def upcase_ticker