Add UI for adding a catalog price to a series

[php-coder]

On the src/main/webapp/WEB-INF/views/series/info.html page we should add another form to add a catalog price. It should have inputs with price and a catalog name. Also there should be a submit button. Here are the examples that can be helpful:

• List of catalogs:

  mystamps/src/main/webapp/WEB-INF/views/site/index.html

  Lines 174 to 184 in 366f099

  	<div class="form-group">
  	<label for="catalogName" th:text="|#{t_catalog}:|">Catalog:</label>
  	<select id="catalogName" name="catalogName" class="form-control">
  	<option value="michel" th:text="#{t_michel}">Michel</option>
  	<option value="scott" th:text="#{t_scott}">Scott</option>
  	<option value="yvert" th:text="#{t_yvert}">Yvert</option>
  	<option value="gibbons" th:text="#{t_sg}">Gibbons</option>
  	<option value="solovyov" th:text="#{t_solovyov}">Solovyov</option>
  	<option value="zagorski" th:text="#{t_zagorski}">Zagorski</option>
  	</select>
  	</div>

• Price:

  mystamps/src/main/webapp/WEB-INF/views/series/info.html

  Lines 408 to 438 in 366f099

  	<input id="paid-price"
  	type="text"
  	size="5"
  	placeholder="price"
  	th:placeholder="${#strings.unCapitalize(price_msg)}"
  	th:field="*{price}"
  	th:disabled="${paidUser ? null : 'disabled'}"
  	/>
  	<select id="paid-currency"
  	th:field="*{currency}"
  	th:disabled="${paidUser ? null : 'disabled'}">
  	<option value=""></option>
  	<option value="USD">USD</option>
  	<option value="EUR">EUR</option>
  	<option value="RUB">RUB</option>
  	<option value="CZK">CZK</option>
  	<option value="BYN">BYN</option>
  	<option value="UAH">UAH</option>
  	</select>
  	</p>
  	<!--/*/
  	<p th:if="${#fields.hasErrors('price') or #fields.hasErrors('currency')}" th:classappend="has-error">
  	<span id="paid-price.errors"
  	class="help-block"
  	th:each="error : ${#fields.errors('price')}"
  	th:text="${error}"></span>
  	<span id="paid-currency.errors"
  	class="help-block"
  	th:each="error : ${#fields.errors('currency')}"
  	th:text="${error}"></span>
  	</p>

When we submit a form, it should send a PATCH request to API /series/{id} with

[
  { "op": "add", "path": "/michel_price", "value": <price> }
]

and reload a page on success. The value of path depends on a value of catalog name -- for Michel catalog, we use "/michel_price" but for Scott it should be "/scott_price" and so on.

It should show an error when server returns an error. Note that there can be 2 type of errors -- general (for a whole form) and validation error (for a particular field).

Part of #1340

[php-coder]

Note that there can be 2 type of errors -- general (for a whole form) and validation error (for a particular field).

The error handling should be the same as in SeriesSaleImportForm and SimilarSeriesForm