Skip confirmation step on email subscription

[Jaskon]

When user is logged in with the same email he tries to subscribe According to #1174

[codecov[bot]]

Codecov Report

Patch coverage: 90.00% and project coverage change: +0.08 :tada:

Comparison is base (07667c8) 58.63% compared to head (6b001f2) 58.71%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #1646 +/- ## ========================================== + Coverage 58.63% 58.71% +0.08% ========================================== Files 128 128 Lines 2877 2885 +8 Branches 730 697 -33 ========================================== + Hits 1687 1694 +7 - Misses 1065 1187 +122 + Partials 125 4 -121 ``` | [Impacted Files](https://app.codecov.io/gh/umputun/remark42/pull/1646?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Umputun) | Coverage Δ | | |---|---|---| | [frontend/apps/remark42/app/common/static-store.ts](https://app.codecov.io/gh/umputun/remark42/pull/1646?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Umputun#diff-ZnJvbnRlbmQvYXBwcy9yZW1hcms0Mi9hcHAvY29tbW9uL3N0YXRpYy1zdG9yZS50cw==) | `100.00% <ø> (ø)` | | | [frontend/apps/remark42/app/common/types.ts](https://app.codecov.io/gh/umputun/remark42/pull/1646?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Umputun#diff-ZnJvbnRlbmQvYXBwcy9yZW1hcms0Mi9hcHAvY29tbW9uL3R5cGVzLnRz) | `100.00% <ø> (ø)` | | | [frontend/apps/remark42/app/utils/errorUtils.ts](https://app.codecov.io/gh/umputun/remark42/pull/1646?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Umputun#diff-ZnJvbnRlbmQvYXBwcy9yZW1hcms0Mi9hcHAvdXRpbHMvZXJyb3JVdGlscy50cw==) | `84.61% <ø> (ø)` | | | [frontend/apps/remark42/app/common/api.ts](https://app.codecov.io/gh/umputun/remark42/pull/1646?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Umputun#diff-ZnJvbnRlbmQvYXBwcy9yZW1hcms0Mi9hcHAvY29tbW9uL2FwaS50cw==) | `72.09% <66.66%> (ø)` | | | [...ribe-by-email/comment-form\_\_subscribe-by-email.tsx](https://app.codecov.io/gh/umputun/remark42/pull/1646?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Umputun#diff-ZnJvbnRlbmQvYXBwcy9yZW1hcms0Mi9hcHAvY29tcG9uZW50cy9jb21tZW50LWZvcm0vX19zdWJzY3JpYmUtYnktZW1haWwvY29tbWVudC1mb3JtX19zdWJzY3JpYmUtYnktZW1haWwudHN4) | `90.40% <93.75%> (-0.20%)` | :arrow_down: | | [frontend/apps/remark42/app/common/fetcher.ts](https://app.codecov.io/gh/umputun/remark42/pull/1646?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Umputun#diff-ZnJvbnRlbmQvYXBwcy9yZW1hcms0Mi9hcHAvY29tbW9uL2ZldGNoZXIudHM=) | `94.82% <100.00%> (ø)` | | ... and [24 files with indirect coverage changes](https://app.codecov.io/gh/umputun/remark42/pull/1646/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Umputun)

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[Jaskon]

1645 changes are also here. They were required for this change and I was forced to merge that branch into this one.

[Jaskon]

@paskal Could you please review it again? Added a handler for 409 http error.

[paskal]

Works like a charm! Please rebase and we'll merge it.