Create UI: cannot target banner FF

**Describe the bug in current situation**
Create UI (and possibly other UIs -- to be tested and fixed in this ticket is practical) show the default banner even when they are targeted for a different banner.

**Link bug to the User Story**
Not at this time.

**Impact of this bug**
Cannot show some users/orgs a different banner than everyone else.

**Chance of Occurring (high/medium/low/very low)**
Reproduces easily.

**Pre Conditions: which Env, any pre-requesites or assumptions to execute steps?**
I found this in Test but it likely reproduces in Dev and Prod.
See Steps to Reproduce.

**Steps to Reproduce**
Steps to reproduce the behavior:
1. in LaunchDarkly, target a user or org for a different `banner-text`
2. login as that user or org
3. navigate to a filing in Create UI (later, try other UIs)
4. observe that the targeted banner is not being displayed

**Actual/ observed behavior/ results**
The targeted banner is not being displayed.
Note that the targeted banner is visible in the LaunchDarkly network traffic (`context` call).

**Expected behavior**
The targeted banner is displayed.

**Screenshots/ Visual Reference/ Source**
Not applicable.

**Root Cause Analysis (RCA) results**
I believe the root cause is that the banner string that is displayed is not reactive -- it is displaying the initial value (when the LD user is "anonymous") and not picking up the targeted value (when the LD user/org is identified).