High memory consumption from Crypto Wallets

[ryanml]

Description

Steps to Reproduce

1. Clean profile, install crypto wallets
2. Pre account creation, import, note relatively low memory usage of the Crypto Wallets extension (<=100mb)
3. Create an account

Actual result:

4. On the seed phrase recovery screen, note the very high memory usage (>=550mb)
5. Note the continued high memory usage while using the extension, with spikes up after unlocking
   

Expected result:

Much more reasonable memory usage

Reproduces how often:

100%

[srirambv]

Verification passed on

Brave	1.20.89 Chromium: 88.0.4324.96 (Official Build) beta (64-bit)
Revision	68dba2d8a0b149a1d3afac56fa74648032bcf46b-refs/branch-heads/4324@{#1784}
OS	Linux
Component	1.0.22 Dev

• Verified memory usage is low compared to before
  

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Verification passed on

Brave	1.19.86 Chromium: 88.0.4324.96 (Official Build) (64-bit)
Revision	68dba2d8a0b149a1d3afac56fa74648032bcf46b-refs/branch-heads/4324@{#1784}
OS	Windows 10 OS Version 2009 (Build 19042.746)
Component	1.0.22 Dev

• Verified memory usage is low compared to before
  

---

Verification passed on

Brave	1.21.21 Chromium: 88.0.4324.96 (Official Build) nightly (x86_64)
Revision	68dba2d8a0b149a1d3afac56fa74648032bcf46b-refs/branch-heads/4324@{#1784}
OS	macOS Version 10.15.7 (Build 19H114)
Component	1.0.22 Dev

• Verified memory usage is low compared to before
  

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Logged #13774 as a follow-up for investigation