Fix loadNodeConfig loses DB data

[friofry]

Problem

As mentioned in status-im/status-desktop#14929
OverwriteNodeConfigValues loses some data (LogLevel, Waku nodes).
Here is an initial fix: #5527

Since loadNodeConfig is used in different ways in different places, this ticket should be done after #5563 (make paths in NodeConfig consistent) because conf.DataDir = filepath.Join(b.rootDataDir, conf.DataDir) joins 2 absolute paths in some tests.

Another issue: we load the DataDir from the db in conf, err := nodecfg.GetNodeConfigFromDB(b.appDB), then
merge it with the default config conf, err = b.OverwriteNodeConfigValues(inputNodeCfg, conf) (it saves the merged config to the database). But only after that the DataDir is joined with the conf.rootDataDir. Some tests might fail because they contain "../static/test-account" in the DataDir (TestLoginAndMigrationsStillWorkWithExistingDesktopUser).

Implementation

Implement #5563, reuse #5527, fix tests

Notes

from #5527 (review)

But I'm pretty sure there will be problems. It affects many values and it was working before somehow.

[igor-sirotin]

I think it's time to fix this. I'm facing another issue trying to pass TestNetworksOverride in CreateAccountAndLogin:

status-go/protocol/requests/create_account.go

Line 69 in f660be0

TestOverrideNetworks []params.Network `json:"-"` // This is used for testing purposes only

It works on the first run, but on the next Login it overwrites the saved networks with the defaults.

@friofry wanna get back to this issue and try to fix it again? 🙂